Commit | Line | Data |
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f80dba8d MT |
1 | How fio works |
2 | ------------- | |
3 | ||
4 | The first step in getting fio to simulate a desired I/O workload, is writing a | |
5 | job file describing that specific setup. A job file may contain any number of | |
6 | threads and/or files -- the typical contents of the job file is a *global* | |
7 | section defining shared parameters, and one or more job sections describing the | |
8 | jobs involved. When run, fio parses this file and sets everything up as | |
9 | described. If we break down a job from top to bottom, it contains the following | |
10 | basic parameters: | |
11 | ||
12 | `I/O type`_ | |
13 | ||
14 | Defines the I/O pattern issued to the file(s). We may only be reading | |
15 | sequentially from this file(s), or we may be writing randomly. Or even | |
16 | mixing reads and writes, sequentially or randomly. | |
17 | Should we be doing buffered I/O, or direct/raw I/O? | |
18 | ||
19 | `Block size`_ | |
20 | ||
21 | In how large chunks are we issuing I/O? This may be a single value, | |
22 | or it may describe a range of block sizes. | |
23 | ||
24 | `I/O size`_ | |
25 | ||
26 | How much data are we going to be reading/writing. | |
27 | ||
28 | `I/O engine`_ | |
29 | ||
30 | How do we issue I/O? We could be memory mapping the file, we could be | |
31 | using regular read/write, we could be using splice, async I/O, or even | |
32 | SG (SCSI generic sg). | |
33 | ||
34 | `I/O depth`_ | |
35 | ||
36 | If the I/O engine is async, how large a queuing depth do we want to | |
37 | maintain? | |
38 | ||
39 | ||
40 | `Target file/device`_ | |
41 | ||
42 | How many files are we spreading the workload over. | |
43 | ||
44 | `Threads, processes and job synchronization`_ | |
45 | ||
46 | How many threads or processes should we spread this workload over. | |
47 | ||
48 | The above are the basic parameters defined for a workload, in addition there's a | |
49 | multitude of parameters that modify other aspects of how this job behaves. | |
50 | ||
51 | ||
52 | Command line options | |
53 | -------------------- | |
54 | ||
55 | .. option:: --debug=type | |
56 | ||
f50fbdda | 57 | Enable verbose tracing `type` of various fio actions. May be ``all`` for all types |
b034c0dd TK |
58 | or individual types separated by a comma (e.g. ``--debug=file,mem`` will |
59 | enable file and memory debugging). Currently, additional logging is | |
60 | available for: | |
f80dba8d | 61 | |
b034c0dd | 62 | *process* |
f80dba8d | 63 | Dump info related to processes. |
b034c0dd | 64 | *file* |
f80dba8d | 65 | Dump info related to file actions. |
b034c0dd | 66 | *io* |
f80dba8d | 67 | Dump info related to I/O queuing. |
b034c0dd | 68 | *mem* |
f80dba8d | 69 | Dump info related to memory allocations. |
b034c0dd | 70 | *blktrace* |
f80dba8d | 71 | Dump info related to blktrace setup. |
b034c0dd | 72 | *verify* |
f80dba8d | 73 | Dump info related to I/O verification. |
b034c0dd | 74 | *all* |
f80dba8d | 75 | Enable all debug options. |
b034c0dd | 76 | *random* |
f80dba8d | 77 | Dump info related to random offset generation. |
b034c0dd | 78 | *parse* |
f80dba8d | 79 | Dump info related to option matching and parsing. |
b034c0dd | 80 | *diskutil* |
f80dba8d | 81 | Dump info related to disk utilization updates. |
b034c0dd | 82 | *job:x* |
f80dba8d | 83 | Dump info only related to job number x. |
b034c0dd | 84 | *mutex* |
f80dba8d | 85 | Dump info only related to mutex up/down ops. |
b034c0dd | 86 | *profile* |
f80dba8d | 87 | Dump info related to profile extensions. |
b034c0dd | 88 | *time* |
f80dba8d | 89 | Dump info related to internal time keeping. |
b034c0dd | 90 | *net* |
f80dba8d | 91 | Dump info related to networking connections. |
b034c0dd | 92 | *rate* |
f80dba8d | 93 | Dump info related to I/O rate switching. |
b034c0dd | 94 | *compress* |
f80dba8d | 95 | Dump info related to log compress/decompress. |
a02ec45a VF |
96 | *steadystate* |
97 | Dump info related to steadystate detection. | |
98 | *helperthread* | |
99 | Dump info related to the helper thread. | |
100 | *zbd* | |
101 | Dump info related to support for zoned block devices. | |
b034c0dd | 102 | *?* or *help* |
f80dba8d MT |
103 | Show available debug options. |
104 | ||
105 | .. option:: --parse-only | |
106 | ||
25cd4b95 | 107 | Parse options only, don't start any I/O. |
f80dba8d | 108 | |
b9921d1a DZ |
109 | .. option:: --merge-blktrace-only |
110 | ||
111 | Merge blktraces only, don't start any I/O. | |
112 | ||
f80dba8d MT |
113 | .. option:: --output=filename |
114 | ||
115 | Write output to file `filename`. | |
116 | ||
f50fbdda | 117 | .. option:: --output-format=format |
b8f7e412 | 118 | |
f50fbdda | 119 | Set the reporting `format` to `normal`, `terse`, `json`, or `json+`. Multiple |
b8f7e412 TK |
120 | formats can be selected, separated by a comma. `terse` is a CSV based |
121 | format. `json+` is like `json`, except it adds a full dump of the latency | |
122 | buckets. | |
123 | ||
f80dba8d MT |
124 | .. option:: --bandwidth-log |
125 | ||
126 | Generate aggregate bandwidth logs. | |
127 | ||
128 | .. option:: --minimal | |
129 | ||
130 | Print statistics in a terse, semicolon-delimited format. | |
131 | ||
132 | .. option:: --append-terse | |
133 | ||
b034c0dd TK |
134 | Print statistics in selected mode AND terse, semicolon-delimited format. |
135 | **Deprecated**, use :option:`--output-format` instead to select multiple | |
136 | formats. | |
f80dba8d | 137 | |
f50fbdda | 138 | .. option:: --terse-version=version |
f80dba8d | 139 | |
f50fbdda | 140 | Set terse `version` output format (default 3, or 2 or 4 or 5). |
f80dba8d MT |
141 | |
142 | .. option:: --version | |
143 | ||
b8f7e412 | 144 | Print version information and exit. |
f80dba8d MT |
145 | |
146 | .. option:: --help | |
147 | ||
113f0e7c | 148 | Print a summary of the command line options and exit. |
f80dba8d MT |
149 | |
150 | .. option:: --cpuclock-test | |
151 | ||
152 | Perform test and validation of internal CPU clock. | |
153 | ||
113f0e7c | 154 | .. option:: --crctest=[test] |
f80dba8d | 155 | |
b034c0dd TK |
156 | Test the speed of the built-in checksumming functions. If no argument is |
157 | given, all of them are tested. Alternatively, a comma separated list can | |
158 | be passed, in which case the given ones are tested. | |
f80dba8d MT |
159 | |
160 | .. option:: --cmdhelp=command | |
161 | ||
162 | Print help information for `command`. May be ``all`` for all commands. | |
163 | ||
164 | .. option:: --enghelp=[ioengine[,command]] | |
165 | ||
f50fbdda TK |
166 | List all commands defined by `ioengine`, or print help for `command` |
167 | defined by `ioengine`. If no `ioengine` is given, list all | |
b034c0dd | 168 | available ioengines. |
f80dba8d MT |
169 | |
170 | .. option:: --showcmd=jobfile | |
171 | ||
b8f7e412 | 172 | Convert `jobfile` to a set of command-line options. |
f80dba8d MT |
173 | |
174 | .. option:: --readonly | |
175 | ||
4027b2a1 VF |
176 | Turn on safety read-only checks, preventing writes and trims. The |
177 | ``--readonly`` option is an extra safety guard to prevent users from | |
178 | accidentally starting a write or trim workload when that is not desired. | |
179 | Fio will only modify the device under test if | |
180 | `rw=write/randwrite/rw/randrw/trim/randtrim/trimwrite` is given. This | |
181 | safety net can be used as an extra precaution. | |
f80dba8d MT |
182 | |
183 | .. option:: --eta=when | |
184 | ||
b8f7e412 | 185 | Specifies when real-time ETA estimate should be printed. `when` may be |
db37d890 JA |
186 | `always`, `never` or `auto`. `auto` is the default, it prints ETA |
187 | when requested if the output is a TTY. `always` disregards the output | |
188 | type, and prints ETA when requested. `never` never prints ETA. | |
189 | ||
190 | .. option:: --eta-interval=time | |
191 | ||
192 | By default, fio requests client ETA status roughly every second. With | |
193 | this option, the interval is configurable. Fio imposes a minimum | |
194 | allowed time to avoid flooding the console, less than 250 msec is | |
195 | not supported. | |
f80dba8d MT |
196 | |
197 | .. option:: --eta-newline=time | |
198 | ||
947e0fe0 SW |
199 | Force a new line for every `time` period passed. When the unit is omitted, |
200 | the value is interpreted in seconds. | |
f80dba8d MT |
201 | |
202 | .. option:: --status-interval=time | |
203 | ||
aa6cb459 VF |
204 | Force a full status dump of cumulative (from job start) values at `time` |
205 | intervals. This option does *not* provide per-period measurements. So | |
206 | values such as bandwidth are running averages. When the time unit is omitted, | |
c1f4de8a JA |
207 | `time` is interpreted in seconds. Note that using this option with |
208 | ``--output-format=json`` will yield output that technically isn't valid | |
209 | json, since the output will be collated sets of valid json. It will need | |
210 | to be split into valid sets of json after the run. | |
f80dba8d MT |
211 | |
212 | .. option:: --section=name | |
213 | ||
b034c0dd TK |
214 | Only run specified section `name` in job file. Multiple sections can be specified. |
215 | The ``--section`` option allows one to combine related jobs into one file. | |
216 | E.g. one job file could define light, moderate, and heavy sections. Tell | |
217 | fio to run only the "heavy" section by giving ``--section=heavy`` | |
218 | command line option. One can also specify the "write" operations in one | |
219 | section and "verify" operation in another section. The ``--section`` option | |
220 | only applies to job sections. The reserved *global* section is always | |
221 | parsed and used. | |
f80dba8d MT |
222 | |
223 | .. option:: --alloc-size=kb | |
224 | ||
4a419903 VF |
225 | Allocate additional internal smalloc pools of size `kb` in KiB. The |
226 | ``--alloc-size`` option increases shared memory set aside for use by fio. | |
b034c0dd TK |
227 | If running large jobs with randommap enabled, fio can run out of memory. |
228 | Smalloc is an internal allocator for shared structures from a fixed size | |
229 | memory pool and can grow to 16 pools. The pool size defaults to 16MiB. | |
f80dba8d | 230 | |
b034c0dd TK |
231 | NOTE: While running :file:`.fio_smalloc.*` backing store files are visible |
232 | in :file:`/tmp`. | |
f80dba8d MT |
233 | |
234 | .. option:: --warnings-fatal | |
235 | ||
b034c0dd TK |
236 | All fio parser warnings are fatal, causing fio to exit with an |
237 | error. | |
f80dba8d MT |
238 | |
239 | .. option:: --max-jobs=nr | |
240 | ||
f50fbdda | 241 | Set the maximum number of threads/processes to support to `nr`. |
818322cc | 242 | NOTE: On Linux, it may be necessary to increase the shared-memory |
71aa48eb | 243 | limit (:file:`/proc/sys/kernel/shmmax`) if fio runs into errors while |
818322cc | 244 | creating jobs. |
f80dba8d MT |
245 | |
246 | .. option:: --server=args | |
247 | ||
b034c0dd TK |
248 | Start a backend server, with `args` specifying what to listen to. |
249 | See `Client/Server`_ section. | |
f80dba8d MT |
250 | |
251 | .. option:: --daemonize=pidfile | |
252 | ||
b034c0dd | 253 | Background a fio server, writing the pid to the given `pidfile` file. |
f80dba8d MT |
254 | |
255 | .. option:: --client=hostname | |
256 | ||
f50fbdda | 257 | Instead of running the jobs locally, send and run them on the given `hostname` |
71aa48eb | 258 | or set of `hostname`\s. See `Client/Server`_ section. |
f80dba8d MT |
259 | |
260 | .. option:: --remote-config=file | |
261 | ||
f50fbdda | 262 | Tell fio server to load this local `file`. |
f80dba8d MT |
263 | |
264 | .. option:: --idle-prof=option | |
265 | ||
b8f7e412 | 266 | Report CPU idleness. `option` is one of the following: |
113f0e7c SW |
267 | |
268 | **calibrate** | |
269 | Run unit work calibration only and exit. | |
270 | ||
271 | **system** | |
272 | Show aggregate system idleness and unit work. | |
273 | ||
274 | **percpu** | |
275 | As **system** but also show per CPU idleness. | |
f80dba8d MT |
276 | |
277 | .. option:: --inflate-log=log | |
278 | ||
f50fbdda | 279 | Inflate and output compressed `log`. |
f80dba8d MT |
280 | |
281 | .. option:: --trigger-file=file | |
282 | ||
f50fbdda | 283 | Execute trigger command when `file` exists. |
f80dba8d | 284 | |
f50fbdda | 285 | .. option:: --trigger-timeout=time |
f80dba8d | 286 | |
f50fbdda | 287 | Execute trigger at this `time`. |
f80dba8d | 288 | |
f50fbdda | 289 | .. option:: --trigger=command |
f80dba8d | 290 | |
f50fbdda | 291 | Set this `command` as local trigger. |
f80dba8d | 292 | |
f50fbdda | 293 | .. option:: --trigger-remote=command |
f80dba8d | 294 | |
f50fbdda | 295 | Set this `command` as remote trigger. |
f80dba8d MT |
296 | |
297 | .. option:: --aux-path=path | |
298 | ||
f4401bf8 SW |
299 | Use the directory specified by `path` for generated state files instead |
300 | of the current working directory. | |
f80dba8d MT |
301 | |
302 | Any parameters following the options will be assumed to be job files, unless | |
303 | they match a job file parameter. Multiple job files can be listed and each job | |
304 | file will be regarded as a separate group. Fio will :option:`stonewall` | |
305 | execution between each group. | |
306 | ||
307 | ||
308 | Job file format | |
309 | --------------- | |
310 | ||
311 | As previously described, fio accepts one or more job files describing what it is | |
312 | supposed to do. The job file format is the classic ini file, where the names | |
c60ebc45 | 313 | enclosed in [] brackets define the job name. You are free to use any ASCII name |
f80dba8d MT |
314 | you want, except *global* which has special meaning. Following the job name is |
315 | a sequence of zero or more parameters, one per line, that define the behavior of | |
316 | the job. If the first character in a line is a ';' or a '#', the entire line is | |
317 | discarded as a comment. | |
318 | ||
319 | A *global* section sets defaults for the jobs described in that file. A job may | |
320 | override a *global* section parameter, and a job file may even have several | |
321 | *global* sections if so desired. A job is only affected by a *global* section | |
322 | residing above it. | |
323 | ||
f50fbdda TK |
324 | The :option:`--cmdhelp` option also lists all options. If used with a `command` |
325 | argument, :option:`--cmdhelp` will detail the given `command`. | |
f80dba8d MT |
326 | |
327 | See the `examples/` directory for inspiration on how to write job files. Note | |
328 | the copyright and license requirements currently apply to `examples/` files. | |
329 | ||
330 | So let's look at a really simple job file that defines two processes, each | |
331 | randomly reading from a 128MiB file: | |
332 | ||
333 | .. code-block:: ini | |
334 | ||
335 | ; -- start job file -- | |
336 | [global] | |
337 | rw=randread | |
338 | size=128m | |
339 | ||
340 | [job1] | |
341 | ||
342 | [job2] | |
343 | ||
344 | ; -- end job file -- | |
345 | ||
346 | As you can see, the job file sections themselves are empty as all the described | |
347 | parameters are shared. As no :option:`filename` option is given, fio makes up a | |
348 | `filename` for each of the jobs as it sees fit. On the command line, this job | |
349 | would look as follows:: | |
350 | ||
351 | $ fio --name=global --rw=randread --size=128m --name=job1 --name=job2 | |
352 | ||
353 | ||
354 | Let's look at an example that has a number of processes writing randomly to | |
355 | files: | |
356 | ||
357 | .. code-block:: ini | |
358 | ||
359 | ; -- start job file -- | |
360 | [random-writers] | |
361 | ioengine=libaio | |
362 | iodepth=4 | |
363 | rw=randwrite | |
364 | bs=32k | |
365 | direct=0 | |
366 | size=64m | |
367 | numjobs=4 | |
368 | ; -- end job file -- | |
369 | ||
370 | Here we have no *global* section, as we only have one job defined anyway. We | |
371 | want to use async I/O here, with a depth of 4 for each file. We also increased | |
372 | the buffer size used to 32KiB and define numjobs to 4 to fork 4 identical | |
373 | jobs. The result is 4 processes each randomly writing to their own 64MiB | |
374 | file. Instead of using the above job file, you could have given the parameters | |
375 | on the command line. For this case, you would specify:: | |
376 | ||
377 | $ fio --name=random-writers --ioengine=libaio --iodepth=4 --rw=randwrite --bs=32k --direct=0 --size=64m --numjobs=4 | |
378 | ||
379 | When fio is utilized as a basis of any reasonably large test suite, it might be | |
380 | desirable to share a set of standardized settings across multiple job files. | |
381 | Instead of copy/pasting such settings, any section may pull in an external | |
382 | :file:`filename.fio` file with *include filename* directive, as in the following | |
383 | example:: | |
384 | ||
385 | ; -- start job file including.fio -- | |
386 | [global] | |
387 | filename=/tmp/test | |
388 | filesize=1m | |
389 | include glob-include.fio | |
390 | ||
391 | [test] | |
392 | rw=randread | |
393 | bs=4k | |
394 | time_based=1 | |
395 | runtime=10 | |
396 | include test-include.fio | |
397 | ; -- end job file including.fio -- | |
398 | ||
399 | .. code-block:: ini | |
400 | ||
401 | ; -- start job file glob-include.fio -- | |
402 | thread=1 | |
403 | group_reporting=1 | |
404 | ; -- end job file glob-include.fio -- | |
405 | ||
406 | .. code-block:: ini | |
407 | ||
408 | ; -- start job file test-include.fio -- | |
409 | ioengine=libaio | |
410 | iodepth=4 | |
411 | ; -- end job file test-include.fio -- | |
412 | ||
413 | Settings pulled into a section apply to that section only (except *global* | |
414 | section). Include directives may be nested in that any included file may contain | |
415 | further include directive(s). Include files may not contain [] sections. | |
416 | ||
417 | ||
418 | Environment variables | |
419 | ~~~~~~~~~~~~~~~~~~~~~ | |
420 | ||
421 | Fio also supports environment variable expansion in job files. Any sub-string of | |
422 | the form ``${VARNAME}`` as part of an option value (in other words, on the right | |
423 | of the '='), will be expanded to the value of the environment variable called | |
424 | `VARNAME`. If no such environment variable is defined, or `VARNAME` is the | |
425 | empty string, the empty string will be substituted. | |
426 | ||
427 | As an example, let's look at a sample fio invocation and job file:: | |
428 | ||
429 | $ SIZE=64m NUMJOBS=4 fio jobfile.fio | |
430 | ||
431 | .. code-block:: ini | |
432 | ||
433 | ; -- start job file -- | |
434 | [random-writers] | |
435 | rw=randwrite | |
436 | size=${SIZE} | |
437 | numjobs=${NUMJOBS} | |
438 | ; -- end job file -- | |
439 | ||
440 | This will expand to the following equivalent job file at runtime: | |
441 | ||
442 | .. code-block:: ini | |
443 | ||
444 | ; -- start job file -- | |
445 | [random-writers] | |
446 | rw=randwrite | |
447 | size=64m | |
448 | numjobs=4 | |
449 | ; -- end job file -- | |
450 | ||
451 | Fio ships with a few example job files, you can also look there for inspiration. | |
452 | ||
453 | Reserved keywords | |
454 | ~~~~~~~~~~~~~~~~~ | |
455 | ||
456 | Additionally, fio has a set of reserved keywords that will be replaced | |
457 | internally with the appropriate value. Those keywords are: | |
458 | ||
459 | **$pagesize** | |
460 | ||
461 | The architecture page size of the running system. | |
462 | ||
463 | **$mb_memory** | |
464 | ||
465 | Megabytes of total memory in the system. | |
466 | ||
467 | **$ncpus** | |
468 | ||
469 | Number of online available CPUs. | |
470 | ||
471 | These can be used on the command line or in the job file, and will be | |
472 | automatically substituted with the current system values when the job is | |
473 | run. Simple math is also supported on these keywords, so you can perform actions | |
474 | like:: | |
475 | ||
b034c0dd | 476 | size=8*$mb_memory |
f80dba8d MT |
477 | |
478 | and get that properly expanded to 8 times the size of memory in the machine. | |
479 | ||
480 | ||
481 | Job file parameters | |
482 | ------------------- | |
483 | ||
484 | This section describes in details each parameter associated with a job. Some | |
485 | parameters take an option of a given type, such as an integer or a | |
486 | string. Anywhere a numeric value is required, an arithmetic expression may be | |
487 | used, provided it is surrounded by parentheses. Supported operators are: | |
488 | ||
489 | - addition (+) | |
490 | - subtraction (-) | |
491 | - multiplication (*) | |
492 | - division (/) | |
493 | - modulus (%) | |
494 | - exponentiation (^) | |
495 | ||
496 | For time values in expressions, units are microseconds by default. This is | |
497 | different than for time values not in expressions (not enclosed in | |
498 | parentheses). The following types are used: | |
499 | ||
500 | ||
501 | Parameter types | |
502 | ~~~~~~~~~~~~~~~ | |
503 | ||
504 | **str** | |
b034c0dd | 505 | String: A sequence of alphanumeric characters. |
f80dba8d MT |
506 | |
507 | **time** | |
008d0feb SW |
508 | Integer with possible time suffix. Without a unit value is interpreted as |
509 | seconds unless otherwise specified. Accepts a suffix of 'd' for days, 'h' for | |
510 | hours, 'm' for minutes, 's' for seconds, 'ms' (or 'msec') for milliseconds and | |
511 | 'us' (or 'usec') for microseconds. For example, use 10m for 10 minutes. | |
f80dba8d MT |
512 | |
513 | .. _int: | |
514 | ||
515 | **int** | |
516 | Integer. A whole number value, which may contain an integer prefix | |
517 | and an integer suffix: | |
518 | ||
b034c0dd | 519 | [*integer prefix*] **number** [*integer suffix*] |
f80dba8d MT |
520 | |
521 | The optional *integer prefix* specifies the number's base. The default | |
522 | is decimal. *0x* specifies hexadecimal. | |
523 | ||
524 | The optional *integer suffix* specifies the number's units, and includes an | |
525 | optional unit prefix and an optional unit. For quantities of data, the | |
947e0fe0 SW |
526 | default unit is bytes. For quantities of time, the default unit is seconds |
527 | unless otherwise specified. | |
f80dba8d | 528 | |
9207a0cb | 529 | With :option:`kb_base`\=1000, fio follows international standards for unit |
f80dba8d MT |
530 | prefixes. To specify power-of-10 decimal values defined in the |
531 | International System of Units (SI): | |
532 | ||
eccce61a TK |
533 | * *K* -- means kilo (K) or 1000 |
534 | * *M* -- means mega (M) or 1000**2 | |
535 | * *G* -- means giga (G) or 1000**3 | |
536 | * *T* -- means tera (T) or 1000**4 | |
537 | * *P* -- means peta (P) or 1000**5 | |
f80dba8d MT |
538 | |
539 | To specify power-of-2 binary values defined in IEC 80000-13: | |
540 | ||
eccce61a TK |
541 | * *Ki* -- means kibi (Ki) or 1024 |
542 | * *Mi* -- means mebi (Mi) or 1024**2 | |
543 | * *Gi* -- means gibi (Gi) or 1024**3 | |
544 | * *Ti* -- means tebi (Ti) or 1024**4 | |
545 | * *Pi* -- means pebi (Pi) or 1024**5 | |
f80dba8d | 546 | |
9207a0cb | 547 | With :option:`kb_base`\=1024 (the default), the unit prefixes are opposite |
f80dba8d MT |
548 | from those specified in the SI and IEC 80000-13 standards to provide |
549 | compatibility with old scripts. For example, 4k means 4096. | |
550 | ||
551 | For quantities of data, an optional unit of 'B' may be included | |
b8f7e412 | 552 | (e.g., 'kB' is the same as 'k'). |
f80dba8d MT |
553 | |
554 | The *integer suffix* is not case sensitive (e.g., m/mi mean mebi/mega, | |
555 | not milli). 'b' and 'B' both mean byte, not bit. | |
556 | ||
9207a0cb | 557 | Examples with :option:`kb_base`\=1000: |
f80dba8d MT |
558 | |
559 | * *4 KiB*: 4096, 4096b, 4096B, 4ki, 4kib, 4kiB, 4Ki, 4KiB | |
560 | * *1 MiB*: 1048576, 1mi, 1024ki | |
561 | * *1 MB*: 1000000, 1m, 1000k | |
562 | * *1 TiB*: 1099511627776, 1ti, 1024gi, 1048576mi | |
563 | * *1 TB*: 1000000000, 1t, 1000m, 1000000k | |
564 | ||
9207a0cb | 565 | Examples with :option:`kb_base`\=1024 (default): |
f80dba8d MT |
566 | |
567 | * *4 KiB*: 4096, 4096b, 4096B, 4k, 4kb, 4kB, 4K, 4KB | |
568 | * *1 MiB*: 1048576, 1m, 1024k | |
569 | * *1 MB*: 1000000, 1mi, 1000ki | |
570 | * *1 TiB*: 1099511627776, 1t, 1024g, 1048576m | |
571 | * *1 TB*: 1000000000, 1ti, 1000mi, 1000000ki | |
572 | ||
573 | To specify times (units are not case sensitive): | |
574 | ||
575 | * *D* -- means days | |
576 | * *H* -- means hours | |
4502cb42 | 577 | * *M* -- means minutes |
f80dba8d MT |
578 | * *s* -- or sec means seconds (default) |
579 | * *ms* -- or *msec* means milliseconds | |
580 | * *us* -- or *usec* means microseconds | |
581 | ||
582 | If the option accepts an upper and lower range, use a colon ':' or | |
583 | minus '-' to separate such values. See :ref:`irange <irange>`. | |
4502cb42 SW |
584 | If the lower value specified happens to be larger than the upper value |
585 | the two values are swapped. | |
f80dba8d MT |
586 | |
587 | .. _bool: | |
588 | ||
589 | **bool** | |
590 | Boolean. Usually parsed as an integer, however only defined for | |
591 | true and false (1 and 0). | |
592 | ||
593 | .. _irange: | |
594 | ||
595 | **irange** | |
596 | Integer range with suffix. Allows value range to be given, such as | |
c60ebc45 | 597 | 1024-4096. A colon may also be used as the separator, e.g. 1k:4k. If the |
f80dba8d MT |
598 | option allows two sets of ranges, they can be specified with a ',' or '/' |
599 | delimiter: 1k-4k/8k-32k. Also see :ref:`int <int>`. | |
600 | ||
601 | **float_list** | |
602 | A list of floating point numbers, separated by a ':' character. | |
603 | ||
f5c3bcf2 TK |
604 | With the above in mind, here follows the complete list of fio job parameters. |
605 | ||
f80dba8d MT |
606 | |
607 | Units | |
608 | ~~~~~ | |
609 | ||
610 | .. option:: kb_base=int | |
611 | ||
612 | Select the interpretation of unit prefixes in input parameters. | |
613 | ||
614 | **1000** | |
615 | Inputs comply with IEC 80000-13 and the International | |
616 | System of Units (SI). Use: | |
617 | ||
618 | - power-of-2 values with IEC prefixes (e.g., KiB) | |
619 | - power-of-10 values with SI prefixes (e.g., kB) | |
620 | ||
621 | **1024** | |
622 | Compatibility mode (default). To avoid breaking old scripts: | |
623 | ||
624 | - power-of-2 values with SI prefixes | |
625 | - power-of-10 values with IEC prefixes | |
626 | ||
627 | See :option:`bs` for more details on input parameters. | |
628 | ||
629 | Outputs always use correct prefixes. Most outputs include both | |
630 | side-by-side, like:: | |
631 | ||
632 | bw=2383.3kB/s (2327.4KiB/s) | |
633 | ||
634 | If only one value is reported, then kb_base selects the one to use: | |
635 | ||
636 | **1000** -- SI prefixes | |
637 | ||
638 | **1024** -- IEC prefixes | |
639 | ||
640 | .. option:: unit_base=int | |
641 | ||
642 | Base unit for reporting. Allowed values are: | |
643 | ||
644 | **0** | |
645 | Use auto-detection (default). | |
646 | **8** | |
647 | Byte based. | |
648 | **1** | |
649 | Bit based. | |
650 | ||
651 | ||
f80dba8d MT |
652 | Job description |
653 | ~~~~~~~~~~~~~~~ | |
654 | ||
655 | .. option:: name=str | |
656 | ||
657 | ASCII name of the job. This may be used to override the name printed by fio | |
658 | for this job. Otherwise the job name is used. On the command line this | |
659 | parameter has the special purpose of also signaling the start of a new job. | |
660 | ||
661 | .. option:: description=str | |
662 | ||
663 | Text description of the job. Doesn't do anything except dump this text | |
664 | description when this job is run. It's not parsed. | |
665 | ||
666 | .. option:: loops=int | |
667 | ||
668 | Run the specified number of iterations of this job. Used to repeat the same | |
669 | workload a given number of times. Defaults to 1. | |
670 | ||
671 | .. option:: numjobs=int | |
672 | ||
79591fa9 TK |
673 | Create the specified number of clones of this job. Each clone of job |
674 | is spawned as an independent thread or process. May be used to setup a | |
f80dba8d MT |
675 | larger number of threads/processes doing the same thing. Each thread is |
676 | reported separately; to see statistics for all clones as a whole, use | |
677 | :option:`group_reporting` in conjunction with :option:`new_group`. | |
a47b697c | 678 | See :option:`--max-jobs`. Default: 1. |
f80dba8d MT |
679 | |
680 | ||
681 | Time related parameters | |
682 | ~~~~~~~~~~~~~~~~~~~~~~~ | |
683 | ||
684 | .. option:: runtime=time | |
685 | ||
f75ede1d | 686 | Tell fio to terminate processing after the specified period of time. It |
f80dba8d | 687 | can be quite hard to determine for how long a specified job will run, so |
f75ede1d | 688 | this parameter is handy to cap the total runtime to a given time. When |
804c0839 | 689 | the unit is omitted, the value is interpreted in seconds. |
f80dba8d MT |
690 | |
691 | .. option:: time_based | |
692 | ||
693 | If set, fio will run for the duration of the :option:`runtime` specified | |
694 | even if the file(s) are completely read or written. It will simply loop over | |
695 | the same workload as many times as the :option:`runtime` allows. | |
696 | ||
a881438b | 697 | .. option:: startdelay=irange(time) |
f80dba8d | 698 | |
947e0fe0 SW |
699 | Delay the start of job for the specified amount of time. Can be a single |
700 | value or a range. When given as a range, each thread will choose a value | |
701 | randomly from within the range. Value is in seconds if a unit is omitted. | |
f80dba8d MT |
702 | |
703 | .. option:: ramp_time=time | |
704 | ||
705 | If set, fio will run the specified workload for this amount of time before | |
706 | logging any performance numbers. Useful for letting performance settle | |
707 | before logging results, thus minimizing the runtime required for stable | |
708 | results. Note that the ``ramp_time`` is considered lead in time for a job, | |
709 | thus it will increase the total runtime if a special timeout or | |
f75ede1d SW |
710 | :option:`runtime` is specified. When the unit is omitted, the value is |
711 | given in seconds. | |
f80dba8d MT |
712 | |
713 | .. option:: clocksource=str | |
714 | ||
715 | Use the given clocksource as the base of timing. The supported options are: | |
716 | ||
717 | **gettimeofday** | |
718 | :manpage:`gettimeofday(2)` | |
719 | ||
720 | **clock_gettime** | |
721 | :manpage:`clock_gettime(2)` | |
722 | ||
723 | **cpu** | |
724 | Internal CPU clock source | |
725 | ||
726 | cpu is the preferred clocksource if it is reliable, as it is very fast (and | |
727 | fio is heavy on time calls). Fio will automatically use this clocksource if | |
728 | it's supported and considered reliable on the system it is running on, | |
729 | unless another clocksource is specifically set. For x86/x86-64 CPUs, this | |
730 | means supporting TSC Invariant. | |
731 | ||
732 | .. option:: gtod_reduce=bool | |
733 | ||
734 | Enable all of the :manpage:`gettimeofday(2)` reducing options | |
f75ede1d | 735 | (:option:`disable_clat`, :option:`disable_slat`, :option:`disable_bw_measurement`) plus |
f80dba8d MT |
736 | reduce precision of the timeout somewhat to really shrink the |
737 | :manpage:`gettimeofday(2)` call count. With this option enabled, we only do | |
738 | about 0.4% of the :manpage:`gettimeofday(2)` calls we would have done if all | |
739 | time keeping was enabled. | |
740 | ||
741 | .. option:: gtod_cpu=int | |
742 | ||
743 | Sometimes it's cheaper to dedicate a single thread of execution to just | |
744 | getting the current time. Fio (and databases, for instance) are very | |
745 | intensive on :manpage:`gettimeofday(2)` calls. With this option, you can set | |
746 | one CPU aside for doing nothing but logging current time to a shared memory | |
747 | location. Then the other threads/processes that run I/O workloads need only | |
748 | copy that segment, instead of entering the kernel with a | |
749 | :manpage:`gettimeofday(2)` call. The CPU set aside for doing these time | |
750 | calls will be excluded from other uses. Fio will manually clear it from the | |
751 | CPU mask of other jobs. | |
752 | ||
753 | ||
754 | Target file/device | |
755 | ~~~~~~~~~~~~~~~~~~ | |
756 | ||
757 | .. option:: directory=str | |
758 | ||
759 | Prefix filenames with this directory. Used to place files in a different | |
760 | location than :file:`./`. You can specify a number of directories by | |
761 | separating the names with a ':' character. These directories will be | |
02dd2689 | 762 | assigned equally distributed to job clones created by :option:`numjobs` as |
f80dba8d MT |
763 | long as they are using generated filenames. If specific `filename(s)` are |
764 | set fio will use the first listed directory, and thereby matching the | |
f4401bf8 SW |
765 | `filename` semantic (which generates a file for each clone if not |
766 | specified, but lets all clones use the same file if set). | |
f80dba8d | 767 | |
3b803fe1 SW |
768 | See the :option:`filename` option for information on how to escape "``:``" |
769 | characters within the directory path itself. | |
f80dba8d | 770 | |
f4401bf8 SW |
771 | Note: To control the directory fio will use for internal state files |
772 | use :option:`--aux-path`. | |
773 | ||
f80dba8d MT |
774 | .. option:: filename=str |
775 | ||
776 | Fio normally makes up a `filename` based on the job name, thread number, and | |
02dd2689 SW |
777 | file number (see :option:`filename_format`). If you want to share files |
778 | between threads in a job or several | |
79591fa9 TK |
779 | jobs with fixed file paths, specify a `filename` for each of them to override |
780 | the default. If the ioengine is file based, you can specify a number of files | |
781 | by separating the names with a ':' colon. So if you wanted a job to open | |
782 | :file:`/dev/sda` and :file:`/dev/sdb` as the two working files, you would use | |
783 | ``filename=/dev/sda:/dev/sdb``. This also means that whenever this option is | |
784 | specified, :option:`nrfiles` is ignored. The size of regular files specified | |
02dd2689 | 785 | by this option will be :option:`size` divided by number of files unless an |
79591fa9 TK |
786 | explicit size is specified by :option:`filesize`. |
787 | ||
3b803fe1 | 788 | Each colon in the wanted path must be escaped with a ``\`` |
02dd2689 SW |
789 | character. For instance, if the path is :file:`/dev/dsk/foo@3,0:c` then you |
790 | would use ``filename=/dev/dsk/foo@3,0\:c`` and if the path is | |
3b803fe1 | 791 | :file:`F:\\filename` then you would use ``filename=F\:\filename``. |
02dd2689 | 792 | |
f80dba8d MT |
793 | On Windows, disk devices are accessed as :file:`\\\\.\\PhysicalDrive0` for |
794 | the first device, :file:`\\\\.\\PhysicalDrive1` for the second etc. | |
795 | Note: Windows and FreeBSD prevent write access to areas | |
02dd2689 SW |
796 | of the disk containing in-use data (e.g. filesystems). |
797 | ||
798 | The filename "`-`" is a reserved name, meaning *stdin* or *stdout*. Which | |
799 | of the two depends on the read/write direction set. | |
f80dba8d MT |
800 | |
801 | .. option:: filename_format=str | |
802 | ||
803 | If sharing multiple files between jobs, it is usually necessary to have fio | |
804 | generate the exact names that you want. By default, fio will name a file | |
805 | based on the default file format specification of | |
806 | :file:`jobname.jobnumber.filenumber`. With this option, that can be | |
807 | customized. Fio will recognize and replace the following keywords in this | |
808 | string: | |
809 | ||
810 | **$jobname** | |
811 | The name of the worker thread or process. | |
8d53c5f8 TG |
812 | **$clientuid** |
813 | IP of the fio process when using client/server mode. | |
f80dba8d MT |
814 | **$jobnum** |
815 | The incremental number of the worker thread or process. | |
816 | **$filenum** | |
817 | The incremental number of the file for that worker thread or | |
818 | process. | |
819 | ||
820 | To have dependent jobs share a set of files, this option can be set to have | |
821 | fio generate filenames that are shared between the two. For instance, if | |
822 | :file:`testfiles.$filenum` is specified, file number 4 for any job will be | |
823 | named :file:`testfiles.4`. The default of :file:`$jobname.$jobnum.$filenum` | |
824 | will be used if no other format specifier is given. | |
825 | ||
645943c0 JB |
826 | If you specify a path then the directories will be created up to the |
827 | main directory for the file. So for example if you specify | |
828 | ``filename_format=a/b/c/$jobnum`` then the directories a/b/c will be | |
829 | created before the file setup part of the job. If you specify | |
830 | :option:`directory` then the path will be relative that directory, | |
831 | otherwise it is treated as the absolute path. | |
832 | ||
f80dba8d MT |
833 | .. option:: unique_filename=bool |
834 | ||
835 | To avoid collisions between networked clients, fio defaults to prefixing any | |
836 | generated filenames (with a directory specified) with the source of the | |
837 | client connecting. To disable this behavior, set this option to 0. | |
838 | ||
839 | .. option:: opendir=str | |
840 | ||
841 | Recursively open any files below directory `str`. | |
842 | ||
843 | .. option:: lockfile=str | |
844 | ||
845 | Fio defaults to not locking any files before it does I/O to them. If a file | |
846 | or file descriptor is shared, fio can serialize I/O to that file to make the | |
847 | end result consistent. This is usual for emulating real workloads that share | |
848 | files. The lock modes are: | |
849 | ||
850 | **none** | |
851 | No locking. The default. | |
852 | **exclusive** | |
853 | Only one thread or process may do I/O at a time, excluding all | |
854 | others. | |
855 | **readwrite** | |
856 | Read-write locking on the file. Many readers may | |
857 | access the file at the same time, but writes get exclusive access. | |
858 | ||
859 | .. option:: nrfiles=int | |
860 | ||
79591fa9 TK |
861 | Number of files to use for this job. Defaults to 1. The size of files |
862 | will be :option:`size` divided by this unless explicit size is specified by | |
863 | :option:`filesize`. Files are created for each thread separately, and each | |
864 | file will have a file number within its name by default, as explained in | |
865 | :option:`filename` section. | |
866 | ||
f80dba8d MT |
867 | |
868 | .. option:: openfiles=int | |
869 | ||
870 | Number of files to keep open at the same time. Defaults to the same as | |
871 | :option:`nrfiles`, can be set smaller to limit the number simultaneous | |
872 | opens. | |
873 | ||
874 | .. option:: file_service_type=str | |
875 | ||
876 | Defines how fio decides which file from a job to service next. The following | |
877 | types are defined: | |
878 | ||
879 | **random** | |
880 | Choose a file at random. | |
881 | ||
882 | **roundrobin** | |
883 | Round robin over opened files. This is the default. | |
884 | ||
885 | **sequential** | |
886 | Finish one file before moving on to the next. Multiple files can | |
f50fbdda | 887 | still be open depending on :option:`openfiles`. |
f80dba8d MT |
888 | |
889 | **zipf** | |
c60ebc45 | 890 | Use a *Zipf* distribution to decide what file to access. |
f80dba8d MT |
891 | |
892 | **pareto** | |
c60ebc45 | 893 | Use a *Pareto* distribution to decide what file to access. |
f80dba8d | 894 | |
dd3503d3 | 895 | **normal** |
c60ebc45 | 896 | Use a *Gaussian* (normal) distribution to decide what file to |
f80dba8d MT |
897 | access. |
898 | ||
dd3503d3 SW |
899 | **gauss** |
900 | Alias for normal. | |
901 | ||
f80dba8d MT |
902 | For *random*, *roundrobin*, and *sequential*, a postfix can be appended to |
903 | tell fio how many I/Os to issue before switching to a new file. For example, | |
904 | specifying ``file_service_type=random:8`` would cause fio to issue | |
905 | 8 I/Os before selecting a new file at random. For the non-uniform | |
906 | distributions, a floating point postfix can be given to influence how the | |
907 | distribution is skewed. See :option:`random_distribution` for a description | |
908 | of how that would work. | |
909 | ||
910 | .. option:: ioscheduler=str | |
911 | ||
912 | Attempt to switch the device hosting the file to the specified I/O scheduler | |
913 | before running. | |
914 | ||
915 | .. option:: create_serialize=bool | |
916 | ||
917 | If true, serialize the file creation for the jobs. This may be handy to | |
918 | avoid interleaving of data files, which may greatly depend on the filesystem | |
a47b697c | 919 | used and even the number of processors in the system. Default: true. |
f80dba8d MT |
920 | |
921 | .. option:: create_fsync=bool | |
922 | ||
22413915 | 923 | :manpage:`fsync(2)` the data file after creation. This is the default. |
f80dba8d MT |
924 | |
925 | .. option:: create_on_open=bool | |
926 | ||
730bd7d9 SW |
927 | If true, don't pre-create files but allow the job's open() to create a file |
928 | when it's time to do I/O. Default: false -- pre-create all necessary files | |
929 | when the job starts. | |
f80dba8d MT |
930 | |
931 | .. option:: create_only=bool | |
932 | ||
933 | If true, fio will only run the setup phase of the job. If files need to be | |
4502cb42 | 934 | laid out or updated on disk, only that will be done -- the actual job contents |
a47b697c | 935 | are not executed. Default: false. |
f80dba8d MT |
936 | |
937 | .. option:: allow_file_create=bool | |
938 | ||
730bd7d9 SW |
939 | If true, fio is permitted to create files as part of its workload. If this |
940 | option is false, then fio will error out if | |
f80dba8d MT |
941 | the files it needs to use don't already exist. Default: true. |
942 | ||
943 | .. option:: allow_mounted_write=bool | |
944 | ||
c60ebc45 | 945 | If this isn't set, fio will abort jobs that are destructive (e.g. that write) |
f80dba8d MT |
946 | to what appears to be a mounted device or partition. This should help catch |
947 | creating inadvertently destructive tests, not realizing that the test will | |
b1db0375 TK |
948 | destroy data on the mounted file system. Note that some platforms don't allow |
949 | writing against a mounted device regardless of this option. Default: false. | |
f80dba8d MT |
950 | |
951 | .. option:: pre_read=bool | |
952 | ||
953 | If this is given, files will be pre-read into memory before starting the | |
954 | given I/O operation. This will also clear the :option:`invalidate` flag, | |
955 | since it is pointless to pre-read and then drop the cache. This will only | |
956 | work for I/O engines that are seek-able, since they allow you to read the | |
a47b697c SW |
957 | same data multiple times. Thus it will not work on non-seekable I/O engines |
958 | (e.g. network, splice). Default: false. | |
f80dba8d MT |
959 | |
960 | .. option:: unlink=bool | |
961 | ||
962 | Unlink the job files when done. Not the default, as repeated runs of that | |
a47b697c SW |
963 | job would then waste time recreating the file set again and again. Default: |
964 | false. | |
f80dba8d MT |
965 | |
966 | .. option:: unlink_each_loop=bool | |
967 | ||
a47b697c | 968 | Unlink job files after each iteration or loop. Default: false. |
f80dba8d | 969 | |
7b865a2f BVA |
970 | .. option:: zonemode=str |
971 | ||
972 | Accepted values are: | |
973 | ||
974 | **none** | |
b8dd9750 HH |
975 | The :option:`zonerange`, :option:`zonesize`, |
976 | :option `zonecapacity` and option:`zoneskip` | |
977 | parameters are ignored. | |
7b865a2f BVA |
978 | **strided** |
979 | I/O happens in a single zone until | |
980 | :option:`zonesize` bytes have been transferred. | |
981 | After that number of bytes has been | |
982 | transferred processing of the next zone | |
b8dd9750 | 983 | starts. :option `zonecapacity` is ignored. |
7b865a2f BVA |
984 | **zbd** |
985 | Zoned block device mode. I/O happens | |
986 | sequentially in each zone, even if random I/O | |
987 | has been selected. Random I/O happens across | |
988 | all zones instead of being restricted to a | |
989 | single zone. The :option:`zoneskip` parameter | |
990 | is ignored. :option:`zonerange` and | |
991 | :option:`zonesize` must be identical. | |
992 | ||
5faddc64 | 993 | .. option:: zonerange=int |
f80dba8d | 994 | |
7b865a2f BVA |
995 | Size of a single zone. See also :option:`zonesize` and |
996 | :option:`zoneskip`. | |
f80dba8d | 997 | |
5faddc64 | 998 | .. option:: zonesize=int |
f80dba8d | 999 | |
7b865a2f BVA |
1000 | For :option:`zonemode` =strided, this is the number of bytes to |
1001 | transfer before skipping :option:`zoneskip` bytes. If this parameter | |
1002 | is smaller than :option:`zonerange` then only a fraction of each zone | |
1003 | with :option:`zonerange` bytes will be accessed. If this parameter is | |
1004 | larger than :option:`zonerange` then each zone will be accessed | |
1005 | multiple times before skipping to the next zone. | |
1006 | ||
1007 | For :option:`zonemode` =zbd, this is the size of a single zone. The | |
1008 | :option:`zonerange` parameter is ignored in this mode. | |
f80dba8d | 1009 | |
b8dd9750 HH |
1010 | |
1011 | .. option:: zonecapacity=int | |
1012 | ||
1013 | For :option:`zonemode` =zbd, this defines the capacity of a single zone, | |
1014 | which is the accessible area starting from the zone start address. | |
1015 | This parameter only applies when using :option:`zonemode` =zbd in | |
1016 | combination with regular block devices. If not specified it defaults to | |
1017 | the zone size. If the target device is a zoned block device, the zone | |
1018 | capacity is obtained from the device information and this option is | |
1019 | ignored. | |
1020 | ||
f80dba8d MT |
1021 | .. option:: zoneskip=int |
1022 | ||
7b865a2f BVA |
1023 | For :option:`zonemode` =strided, the number of bytes to skip after |
1024 | :option:`zonesize` bytes of data have been transferred. This parameter | |
1025 | must be zero for :option:`zonemode` =zbd. | |
f80dba8d | 1026 | |
bfbdd35b BVA |
1027 | .. option:: read_beyond_wp=bool |
1028 | ||
1029 | This parameter applies to :option:`zonemode` =zbd only. | |
1030 | ||
1031 | Zoned block devices are block devices that consist of multiple zones. | |
1032 | Each zone has a type, e.g. conventional or sequential. A conventional | |
1033 | zone can be written at any offset that is a multiple of the block | |
1034 | size. Sequential zones must be written sequentially. The position at | |
1035 | which a write must occur is called the write pointer. A zoned block | |
1036 | device can be either drive managed, host managed or host aware. For | |
1037 | host managed devices the host must ensure that writes happen | |
1038 | sequentially. Fio recognizes host managed devices and serializes | |
1039 | writes to sequential zones for these devices. | |
1040 | ||
1041 | If a read occurs in a sequential zone beyond the write pointer then | |
1042 | the zoned block device will complete the read without reading any data | |
1043 | from the storage medium. Since such reads lead to unrealistically high | |
1044 | bandwidth and IOPS numbers fio only reads beyond the write pointer if | |
1045 | explicitly told to do so. Default: false. | |
1046 | ||
59b07544 BVA |
1047 | .. option:: max_open_zones=int |
1048 | ||
1049 | When running a random write test across an entire drive many more | |
1050 | zones will be open than in a typical application workload. Hence this | |
1051 | command line option that allows to limit the number of open zones. The | |
1052 | number of open zones is defined as the number of zones to which write | |
1053 | commands are issued. | |
1054 | ||
a7c2b6fc BVA |
1055 | .. option:: zone_reset_threshold=float |
1056 | ||
1057 | A number between zero and one that indicates the ratio of logical | |
1058 | blocks with data to the total number of logical blocks in the test | |
1059 | above which zones should be reset periodically. | |
1060 | ||
1061 | .. option:: zone_reset_frequency=float | |
1062 | ||
1063 | A number between zero and one that indicates how often a zone reset | |
1064 | should be issued if the zone reset threshold has been exceeded. A zone | |
1065 | reset is submitted after each (1 / zone_reset_frequency) write | |
1066 | requests. This and the previous parameter can be used to simulate | |
1067 | garbage collection activity. | |
1068 | ||
f80dba8d MT |
1069 | |
1070 | I/O type | |
1071 | ~~~~~~~~ | |
1072 | ||
1073 | .. option:: direct=bool | |
1074 | ||
1075 | If value is true, use non-buffered I/O. This is usually O_DIRECT. Note that | |
8e889110 | 1076 | OpenBSD and ZFS on Solaris don't support direct I/O. On Windows the synchronous |
f80dba8d MT |
1077 | ioengines don't support direct I/O. Default: false. |
1078 | ||
1079 | .. option:: atomic=bool | |
1080 | ||
1081 | If value is true, attempt to use atomic direct I/O. Atomic writes are | |
1082 | guaranteed to be stable once acknowledged by the operating system. Only | |
1083 | Linux supports O_ATOMIC right now. | |
1084 | ||
1085 | .. option:: buffered=bool | |
1086 | ||
1087 | If value is true, use buffered I/O. This is the opposite of the | |
1088 | :option:`direct` option. Defaults to true. | |
1089 | ||
1090 | .. option:: readwrite=str, rw=str | |
1091 | ||
1092 | Type of I/O pattern. Accepted values are: | |
1093 | ||
1094 | **read** | |
1095 | Sequential reads. | |
1096 | **write** | |
1097 | Sequential writes. | |
1098 | **trim** | |
3740cfc8 VF |
1099 | Sequential trims (Linux block devices and SCSI |
1100 | character devices only). | |
f80dba8d MT |
1101 | **randread** |
1102 | Random reads. | |
2831be97 SW |
1103 | **randwrite** |
1104 | Random writes. | |
f80dba8d | 1105 | **randtrim** |
3740cfc8 VF |
1106 | Random trims (Linux block devices and SCSI |
1107 | character devices only). | |
f80dba8d MT |
1108 | **rw,readwrite** |
1109 | Sequential mixed reads and writes. | |
1110 | **randrw** | |
1111 | Random mixed reads and writes. | |
1112 | **trimwrite** | |
1113 | Sequential trim+write sequences. Blocks will be trimmed first, | |
1114 | then the same blocks will be written to. | |
1115 | ||
1116 | Fio defaults to read if the option is not specified. For the mixed I/O | |
1117 | types, the default is to split them 50/50. For certain types of I/O the | |
730bd7d9 SW |
1118 | result may still be skewed a bit, since the speed may be different. |
1119 | ||
1120 | It is possible to specify the number of I/Os to do before getting a new | |
1121 | offset by appending ``:<nr>`` to the end of the string given. For a | |
f80dba8d MT |
1122 | random read, it would look like ``rw=randread:8`` for passing in an offset |
1123 | modifier with a value of 8. If the suffix is used with a sequential I/O | |
730bd7d9 SW |
1124 | pattern, then the *<nr>* value specified will be **added** to the generated |
1125 | offset for each I/O turning sequential I/O into sequential I/O with holes. | |
1126 | For instance, using ``rw=write:4k`` will skip 4k for every write. Also see | |
1127 | the :option:`rw_sequencer` option. | |
f80dba8d MT |
1128 | |
1129 | .. option:: rw_sequencer=str | |
1130 | ||
1131 | If an offset modifier is given by appending a number to the ``rw=<str>`` | |
1132 | line, then this option controls how that number modifies the I/O offset | |
1133 | being generated. Accepted values are: | |
1134 | ||
1135 | **sequential** | |
1136 | Generate sequential offset. | |
1137 | **identical** | |
1138 | Generate the same offset. | |
1139 | ||
1140 | ``sequential`` is only useful for random I/O, where fio would normally | |
c60ebc45 | 1141 | generate a new random offset for every I/O. If you append e.g. 8 to randread, |
007c7be9 SW |
1142 | you would get a new random offset for every 8 I/Os. The result would be a |
1143 | seek for only every 8 I/Os, instead of for every I/O. Use ``rw=randread:8`` | |
f80dba8d MT |
1144 | to specify that. As sequential I/O is already sequential, setting |
1145 | ``sequential`` for that would not result in any differences. ``identical`` | |
1146 | behaves in a similar fashion, except it sends the same offset 8 number of | |
1147 | times before generating a new offset. | |
1148 | ||
1149 | .. option:: unified_rw_reporting=bool | |
1150 | ||
1151 | Fio normally reports statistics on a per data direction basis, meaning that | |
1152 | reads, writes, and trims are accounted and reported separately. If this | |
1153 | option is set fio sums the results and report them as "mixed" instead. | |
1154 | ||
1155 | .. option:: randrepeat=bool | |
1156 | ||
1157 | Seed the random number generator used for random I/O patterns in a | |
1158 | predictable way so the pattern is repeatable across runs. Default: true. | |
1159 | ||
1160 | .. option:: allrandrepeat=bool | |
1161 | ||
1162 | Seed all random number generators in a predictable way so results are | |
1163 | repeatable across runs. Default: false. | |
1164 | ||
1165 | .. option:: randseed=int | |
1166 | ||
1167 | Seed the random number generators based on this seed value, to be able to | |
1168 | control what sequence of output is being generated. If not set, the random | |
1169 | sequence depends on the :option:`randrepeat` setting. | |
1170 | ||
1171 | .. option:: fallocate=str | |
1172 | ||
1173 | Whether pre-allocation is performed when laying down files. | |
1174 | Accepted values are: | |
1175 | ||
1176 | **none** | |
1177 | Do not pre-allocate space. | |
1178 | ||
2c3e17be SW |
1179 | **native** |
1180 | Use a platform's native pre-allocation call but fall back to | |
1181 | **none** behavior if it fails/is not implemented. | |
1182 | ||
f80dba8d MT |
1183 | **posix** |
1184 | Pre-allocate via :manpage:`posix_fallocate(3)`. | |
1185 | ||
1186 | **keep** | |
1187 | Pre-allocate via :manpage:`fallocate(2)` with | |
1188 | FALLOC_FL_KEEP_SIZE set. | |
1189 | ||
38ca5f03 TV |
1190 | **truncate** |
1191 | Extend file to final size via :manpage:`ftruncate(2)` | |
1192 | instead of allocating. | |
1193 | ||
f80dba8d MT |
1194 | **0** |
1195 | Backward-compatible alias for **none**. | |
1196 | ||
1197 | **1** | |
1198 | Backward-compatible alias for **posix**. | |
1199 | ||
1200 | May not be available on all supported platforms. **keep** is only available | |
2c3e17be SW |
1201 | on Linux. If using ZFS on Solaris this cannot be set to **posix** |
1202 | because ZFS doesn't support pre-allocation. Default: **native** if any | |
38ca5f03 TV |
1203 | pre-allocation methods except **truncate** are available, **none** if not. |
1204 | ||
1205 | Note that using **truncate** on Windows will interact surprisingly | |
1206 | with non-sequential write patterns. When writing to a file that has | |
1207 | been extended by setting the end-of-file information, Windows will | |
1208 | backfill the unwritten portion of the file up to that offset with | |
1209 | zeroes before issuing the new write. This means that a single small | |
1210 | write to the end of an extended file will stall until the entire | |
1211 | file has been filled with zeroes. | |
f80dba8d MT |
1212 | |
1213 | .. option:: fadvise_hint=str | |
1214 | ||
c712c97a JA |
1215 | Use :manpage:`posix_fadvise(2)` or :manpage:`posix_fadvise(2)` to |
1216 | advise the kernel on what I/O patterns are likely to be issued. | |
1217 | Accepted values are: | |
f80dba8d MT |
1218 | |
1219 | **0** | |
1220 | Backwards-compatible hint for "no hint". | |
1221 | ||
1222 | **1** | |
1223 | Backwards compatible hint for "advise with fio workload type". This | |
1224 | uses **FADV_RANDOM** for a random workload, and **FADV_SEQUENTIAL** | |
1225 | for a sequential workload. | |
1226 | ||
1227 | **sequential** | |
1228 | Advise using **FADV_SEQUENTIAL**. | |
1229 | ||
1230 | **random** | |
1231 | Advise using **FADV_RANDOM**. | |
1232 | ||
8f4b9f24 | 1233 | .. option:: write_hint=str |
f80dba8d | 1234 | |
8f4b9f24 JA |
1235 | Use :manpage:`fcntl(2)` to advise the kernel what life time to expect |
1236 | from a write. Only supported on Linux, as of version 4.13. Accepted | |
1237 | values are: | |
1238 | ||
1239 | **none** | |
1240 | No particular life time associated with this file. | |
1241 | ||
1242 | **short** | |
1243 | Data written to this file has a short life time. | |
1244 | ||
1245 | **medium** | |
1246 | Data written to this file has a medium life time. | |
1247 | ||
1248 | **long** | |
1249 | Data written to this file has a long life time. | |
1250 | ||
1251 | **extreme** | |
1252 | Data written to this file has a very long life time. | |
1253 | ||
1254 | The values are all relative to each other, and no absolute meaning | |
1255 | should be associated with them. | |
f80dba8d MT |
1256 | |
1257 | .. option:: offset=int | |
1258 | ||
82dbb8cb | 1259 | Start I/O at the provided offset in the file, given as either a fixed size in |
83c8b093 JF |
1260 | bytes or a percentage. If a percentage is given, the generated offset will be |
1261 | aligned to the minimum ``blocksize`` or to the value of ``offset_align`` if | |
1262 | provided. Data before the given offset will not be touched. This | |
89978a6b BW |
1263 | effectively caps the file size at `real_size - offset`. Can be combined with |
1264 | :option:`size` to constrain the start and end range of the I/O workload. | |
44bb1142 TK |
1265 | A percentage can be specified by a number between 1 and 100 followed by '%', |
1266 | for example, ``offset=20%`` to specify 20%. | |
f80dba8d | 1267 | |
83c8b093 JF |
1268 | .. option:: offset_align=int |
1269 | ||
1270 | If set to non-zero value, the byte offset generated by a percentage ``offset`` | |
1271 | is aligned upwards to this value. Defaults to 0 meaning that a percentage | |
1272 | offset is aligned to the minimum block size. | |
1273 | ||
f80dba8d MT |
1274 | .. option:: offset_increment=int |
1275 | ||
1276 | If this is provided, then the real offset becomes `offset + offset_increment | |
1277 | * thread_number`, where the thread number is a counter that starts at 0 and | |
1278 | is incremented for each sub-job (i.e. when :option:`numjobs` option is | |
1279 | specified). This option is useful if there are several jobs which are | |
1280 | intended to operate on a file in parallel disjoint segments, with even | |
0b288ba1 VF |
1281 | spacing between the starting points. Percentages can be used for this option. |
1282 | If a percentage is given, the generated offset will be aligned to the minimum | |
1283 | ``blocksize`` or to the value of ``offset_align`` if provided. | |
f80dba8d MT |
1284 | |
1285 | .. option:: number_ios=int | |
1286 | ||
c60ebc45 | 1287 | Fio will normally perform I/Os until it has exhausted the size of the region |
f80dba8d MT |
1288 | set by :option:`size`, or if it exhaust the allocated time (or hits an error |
1289 | condition). With this setting, the range/size can be set independently of | |
c60ebc45 | 1290 | the number of I/Os to perform. When fio reaches this number, it will exit |
f80dba8d MT |
1291 | normally and report status. Note that this does not extend the amount of I/O |
1292 | that will be done, it will only stop fio if this condition is met before | |
1293 | other end-of-job criteria. | |
1294 | ||
1295 | .. option:: fsync=int | |
1296 | ||
730bd7d9 SW |
1297 | If writing to a file, issue an :manpage:`fsync(2)` (or its equivalent) of |
1298 | the dirty data for every number of blocks given. For example, if you give 32 | |
1299 | as a parameter, fio will sync the file after every 32 writes issued. If fio is | |
1300 | using non-buffered I/O, we may not sync the file. The exception is the sg | |
1301 | I/O engine, which synchronizes the disk cache anyway. Defaults to 0, which | |
1302 | means fio does not periodically issue and wait for a sync to complete. Also | |
1303 | see :option:`end_fsync` and :option:`fsync_on_close`. | |
f80dba8d MT |
1304 | |
1305 | .. option:: fdatasync=int | |
1306 | ||
1307 | Like :option:`fsync` but uses :manpage:`fdatasync(2)` to only sync data and | |
44f668d7 | 1308 | not metadata blocks. In Windows, FreeBSD, DragonFlyBSD or OSX there is no |
730bd7d9 SW |
1309 | :manpage:`fdatasync(2)` so this falls back to using :manpage:`fsync(2)`. |
1310 | Defaults to 0, which means fio does not periodically issue and wait for a | |
1311 | data-only sync to complete. | |
f80dba8d MT |
1312 | |
1313 | .. option:: write_barrier=int | |
1314 | ||
2831be97 | 1315 | Make every `N-th` write a barrier write. |
f80dba8d | 1316 | |
f50fbdda | 1317 | .. option:: sync_file_range=str:int |
f80dba8d | 1318 | |
f50fbdda | 1319 | Use :manpage:`sync_file_range(2)` for every `int` number of write |
f80dba8d MT |
1320 | operations. Fio will track range of writes that have happened since the last |
1321 | :manpage:`sync_file_range(2)` call. `str` can currently be one or more of: | |
1322 | ||
1323 | **wait_before** | |
1324 | SYNC_FILE_RANGE_WAIT_BEFORE | |
1325 | **write** | |
1326 | SYNC_FILE_RANGE_WRITE | |
1327 | **wait_after** | |
1328 | SYNC_FILE_RANGE_WAIT_AFTER | |
1329 | ||
1330 | So if you do ``sync_file_range=wait_before,write:8``, fio would use | |
1331 | ``SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE`` for every 8 | |
1332 | writes. Also see the :manpage:`sync_file_range(2)` man page. This option is | |
1333 | Linux specific. | |
1334 | ||
1335 | .. option:: overwrite=bool | |
1336 | ||
1337 | If true, writes to a file will always overwrite existing data. If the file | |
1338 | doesn't already exist, it will be created before the write phase begins. If | |
1339 | the file exists and is large enough for the specified write phase, nothing | |
a47b697c | 1340 | will be done. Default: false. |
f80dba8d MT |
1341 | |
1342 | .. option:: end_fsync=bool | |
1343 | ||
a47b697c SW |
1344 | If true, :manpage:`fsync(2)` file contents when a write stage has completed. |
1345 | Default: false. | |
f80dba8d MT |
1346 | |
1347 | .. option:: fsync_on_close=bool | |
1348 | ||
1349 | If true, fio will :manpage:`fsync(2)` a dirty file on close. This differs | |
a47b697c SW |
1350 | from :option:`end_fsync` in that it will happen on every file close, not |
1351 | just at the end of the job. Default: false. | |
f80dba8d MT |
1352 | |
1353 | .. option:: rwmixread=int | |
1354 | ||
1355 | Percentage of a mixed workload that should be reads. Default: 50. | |
1356 | ||
1357 | .. option:: rwmixwrite=int | |
1358 | ||
1359 | Percentage of a mixed workload that should be writes. If both | |
1360 | :option:`rwmixread` and :option:`rwmixwrite` is given and the values do not | |
1361 | add up to 100%, the latter of the two will be used to override the | |
1362 | first. This may interfere with a given rate setting, if fio is asked to | |
1363 | limit reads or writes to a certain rate. If that is the case, then the | |
1364 | distribution may be skewed. Default: 50. | |
1365 | ||
a87c90fd | 1366 | .. option:: random_distribution=str:float[:float][,str:float][,str:float] |
f80dba8d MT |
1367 | |
1368 | By default, fio will use a completely uniform random distribution when asked | |
1369 | to perform random I/O. Sometimes it is useful to skew the distribution in | |
1370 | specific ways, ensuring that some parts of the data is more hot than others. | |
1371 | fio includes the following distribution models: | |
1372 | ||
1373 | **random** | |
1374 | Uniform random distribution | |
1375 | ||
1376 | **zipf** | |
1377 | Zipf distribution | |
1378 | ||
1379 | **pareto** | |
1380 | Pareto distribution | |
1381 | ||
b2f4b559 | 1382 | **normal** |
c60ebc45 | 1383 | Normal (Gaussian) distribution |
f80dba8d MT |
1384 | |
1385 | **zoned** | |
1386 | Zoned random distribution | |
1387 | ||
59466396 JA |
1388 | **zoned_abs** |
1389 | Zone absolute random distribution | |
1390 | ||
f80dba8d | 1391 | When using a **zipf** or **pareto** distribution, an input value is also |
f50fbdda | 1392 | needed to define the access pattern. For **zipf**, this is the `Zipf |
c60ebc45 | 1393 | theta`. For **pareto**, it's the `Pareto power`. Fio includes a test |
f50fbdda | 1394 | program, :command:`fio-genzipf`, that can be used visualize what the given input |
f80dba8d MT |
1395 | values will yield in terms of hit rates. If you wanted to use **zipf** with |
1396 | a `theta` of 1.2, you would use ``random_distribution=zipf:1.2`` as the | |
1397 | option. If a non-uniform model is used, fio will disable use of the random | |
b2f4b559 SW |
1398 | map. For the **normal** distribution, a normal (Gaussian) deviation is |
1399 | supplied as a value between 0 and 100. | |
f80dba8d | 1400 | |
a87c90fd AK |
1401 | The second, optional float is allowed for **pareto**, **zipf** and **normal** distributions. |
1402 | It allows to set base of distribution in non-default place, giving more control | |
1403 | over most probable outcome. This value is in range [0-1] which maps linearly to | |
1404 | range of possible random values. | |
1405 | Defaults are: random for **pareto** and **zipf**, and 0.5 for **normal**. | |
1406 | If you wanted to use **zipf** with a `theta` of 1.2 centered on 1/4 of allowed value range, | |
1407 | you would use ``random_distibution=zipf:1.2:0.25``. | |
1408 | ||
f80dba8d MT |
1409 | For a **zoned** distribution, fio supports specifying percentages of I/O |
1410 | access that should fall within what range of the file or device. For | |
1411 | example, given a criteria of: | |
1412 | ||
f50fbdda TK |
1413 | * 60% of accesses should be to the first 10% |
1414 | * 30% of accesses should be to the next 20% | |
1415 | * 8% of accesses should be to the next 30% | |
1416 | * 2% of accesses should be to the next 40% | |
f80dba8d MT |
1417 | |
1418 | we can define that through zoning of the random accesses. For the above | |
1419 | example, the user would do:: | |
1420 | ||
1421 | random_distribution=zoned:60/10:30/20:8/30:2/40 | |
1422 | ||
59466396 JA |
1423 | A **zoned_abs** distribution works exactly like the **zoned**, except |
1424 | that it takes absolute sizes. For example, let's say you wanted to | |
1425 | define access according to the following criteria: | |
1426 | ||
1427 | * 60% of accesses should be to the first 20G | |
1428 | * 30% of accesses should be to the next 100G | |
1429 | * 10% of accesses should be to the next 500G | |
1430 | ||
1431 | we can define an absolute zoning distribution with: | |
1432 | ||
1433 | random_distribution=zoned_abs=60/20G:30/100G:10/500g | |
1434 | ||
6a16ece8 JA |
1435 | For both **zoned** and **zoned_abs**, fio supports defining up to |
1436 | 256 separate zones. | |
1437 | ||
59466396 JA |
1438 | Similarly to how :option:`bssplit` works for setting ranges and |
1439 | percentages of block sizes. Like :option:`bssplit`, it's possible to | |
1440 | specify separate zones for reads, writes, and trims. If just one set | |
1441 | is given, it'll apply to all of them. This goes for both **zoned** | |
1442 | **zoned_abs** distributions. | |
f80dba8d MT |
1443 | |
1444 | .. option:: percentage_random=int[,int][,int] | |
1445 | ||
1446 | For a random workload, set how big a percentage should be random. This | |
1447 | defaults to 100%, in which case the workload is fully random. It can be set | |
1448 | from anywhere from 0 to 100. Setting it to 0 would make the workload fully | |
1449 | sequential. Any setting in between will result in a random mix of sequential | |
1450 | and random I/O, at the given percentages. Comma-separated values may be | |
1451 | specified for reads, writes, and trims as described in :option:`blocksize`. | |
1452 | ||
1453 | .. option:: norandommap | |
1454 | ||
1455 | Normally fio will cover every block of the file when doing random I/O. If | |
1456 | this option is given, fio will just get a new random offset without looking | |
1457 | at past I/O history. This means that some blocks may not be read or written, | |
1458 | and that some blocks may be read/written more than once. If this option is | |
1459 | used with :option:`verify` and multiple blocksizes (via :option:`bsrange`), | |
1460 | only intact blocks are verified, i.e., partially-overwritten blocks are | |
47e6a6e5 SW |
1461 | ignored. With an async I/O engine and an I/O depth > 1, it is possible for |
1462 | the same block to be overwritten, which can cause verification errors. Either | |
1463 | do not use norandommap in this case, or also use the lfsr random generator. | |
f80dba8d MT |
1464 | |
1465 | .. option:: softrandommap=bool | |
1466 | ||
1467 | See :option:`norandommap`. If fio runs with the random block map enabled and | |
1468 | it fails to allocate the map, if this option is set it will continue without | |
1469 | a random block map. As coverage will not be as complete as with random maps, | |
1470 | this option is disabled by default. | |
1471 | ||
1472 | .. option:: random_generator=str | |
1473 | ||
f50fbdda | 1474 | Fio supports the following engines for generating I/O offsets for random I/O: |
f80dba8d MT |
1475 | |
1476 | **tausworthe** | |
f50fbdda | 1477 | Strong 2^88 cycle random number generator. |
f80dba8d | 1478 | **lfsr** |
f50fbdda | 1479 | Linear feedback shift register generator. |
f80dba8d | 1480 | **tausworthe64** |
f50fbdda | 1481 | Strong 64-bit 2^258 cycle random number generator. |
f80dba8d MT |
1482 | |
1483 | **tausworthe** is a strong random number generator, but it requires tracking | |
1484 | on the side if we want to ensure that blocks are only read or written | |
f50fbdda | 1485 | once. **lfsr** guarantees that we never generate the same offset twice, and |
f80dba8d | 1486 | it's also less computationally expensive. It's not a true random generator, |
f50fbdda | 1487 | however, though for I/O purposes it's typically good enough. **lfsr** only |
f80dba8d MT |
1488 | works with single block sizes, not with workloads that use multiple block |
1489 | sizes. If used with such a workload, fio may read or write some blocks | |
1490 | multiple times. The default value is **tausworthe**, unless the required | |
1491 | space exceeds 2^32 blocks. If it does, then **tausworthe64** is | |
1492 | selected automatically. | |
1493 | ||
1494 | ||
1495 | Block size | |
1496 | ~~~~~~~~~~ | |
1497 | ||
1498 | .. option:: blocksize=int[,int][,int], bs=int[,int][,int] | |
1499 | ||
1500 | The block size in bytes used for I/O units. Default: 4096. A single value | |
1501 | applies to reads, writes, and trims. Comma-separated values may be | |
1502 | specified for reads, writes, and trims. A value not terminated in a comma | |
1503 | applies to subsequent types. | |
1504 | ||
1505 | Examples: | |
1506 | ||
1507 | **bs=256k** | |
1508 | means 256k for reads, writes and trims. | |
1509 | ||
1510 | **bs=8k,32k** | |
1511 | means 8k for reads, 32k for writes and trims. | |
1512 | ||
1513 | **bs=8k,32k,** | |
1514 | means 8k for reads, 32k for writes, and default for trims. | |
1515 | ||
1516 | **bs=,8k** | |
1517 | means default for reads, 8k for writes and trims. | |
1518 | ||
1519 | **bs=,8k,** | |
b443ae44 | 1520 | means default for reads, 8k for writes, and default for trims. |
f80dba8d MT |
1521 | |
1522 | .. option:: blocksize_range=irange[,irange][,irange], bsrange=irange[,irange][,irange] | |
1523 | ||
1524 | A range of block sizes in bytes for I/O units. The issued I/O unit will | |
1525 | always be a multiple of the minimum size, unless | |
1526 | :option:`blocksize_unaligned` is set. | |
1527 | ||
1528 | Comma-separated ranges may be specified for reads, writes, and trims as | |
1529 | described in :option:`blocksize`. | |
1530 | ||
1531 | Example: ``bsrange=1k-4k,2k-8k``. | |
1532 | ||
1533 | .. option:: bssplit=str[,str][,str] | |
1534 | ||
6a16ece8 JA |
1535 | Sometimes you want even finer grained control of the block sizes |
1536 | issued, not just an even split between them. This option allows you to | |
1537 | weight various block sizes, so that you are able to define a specific | |
1538 | amount of block sizes issued. The format for this option is:: | |
f80dba8d MT |
1539 | |
1540 | bssplit=blocksize/percentage:blocksize/percentage | |
1541 | ||
6a16ece8 JA |
1542 | for as many block sizes as needed. So if you want to define a workload |
1543 | that has 50% 64k blocks, 10% 4k blocks, and 40% 32k blocks, you would | |
1544 | write:: | |
f80dba8d MT |
1545 | |
1546 | bssplit=4k/10:64k/50:32k/40 | |
1547 | ||
6a16ece8 JA |
1548 | Ordering does not matter. If the percentage is left blank, fio will |
1549 | fill in the remaining values evenly. So a bssplit option like this one:: | |
f80dba8d MT |
1550 | |
1551 | bssplit=4k/50:1k/:32k/ | |
1552 | ||
6a16ece8 JA |
1553 | would have 50% 4k ios, and 25% 1k and 32k ios. The percentages always |
1554 | add up to 100, if bssplit is given a range that adds up to more, it | |
1555 | will error out. | |
f80dba8d MT |
1556 | |
1557 | Comma-separated values may be specified for reads, writes, and trims as | |
1558 | described in :option:`blocksize`. | |
1559 | ||
6a16ece8 JA |
1560 | If you want a workload that has 50% 2k reads and 50% 4k reads, while |
1561 | having 90% 4k writes and 10% 8k writes, you would specify:: | |
f80dba8d | 1562 | |
cf04b906 | 1563 | bssplit=2k/50:4k/50,4k/90:8k/10 |
f80dba8d | 1564 | |
6a16ece8 JA |
1565 | Fio supports defining up to 64 different weights for each data |
1566 | direction. | |
1567 | ||
f80dba8d MT |
1568 | .. option:: blocksize_unaligned, bs_unaligned |
1569 | ||
1570 | If set, fio will issue I/O units with any size within | |
1571 | :option:`blocksize_range`, not just multiples of the minimum size. This | |
1572 | typically won't work with direct I/O, as that normally requires sector | |
1573 | alignment. | |
1574 | ||
589e88b7 | 1575 | .. option:: bs_is_seq_rand=bool |
f80dba8d MT |
1576 | |
1577 | If this option is set, fio will use the normal read,write blocksize settings | |
1578 | as sequential,random blocksize settings instead. Any random read or write | |
1579 | will use the WRITE blocksize settings, and any sequential read or write will | |
1580 | use the READ blocksize settings. | |
1581 | ||
1582 | .. option:: blockalign=int[,int][,int], ba=int[,int][,int] | |
1583 | ||
1584 | Boundary to which fio will align random I/O units. Default: | |
1585 | :option:`blocksize`. Minimum alignment is typically 512b for using direct | |
1586 | I/O, though it usually depends on the hardware block size. This option is | |
1587 | mutually exclusive with using a random map for files, so it will turn off | |
1588 | that option. Comma-separated values may be specified for reads, writes, and | |
1589 | trims as described in :option:`blocksize`. | |
1590 | ||
1591 | ||
1592 | Buffers and memory | |
1593 | ~~~~~~~~~~~~~~~~~~ | |
1594 | ||
1595 | .. option:: zero_buffers | |
1596 | ||
1597 | Initialize buffers with all zeros. Default: fill buffers with random data. | |
1598 | ||
1599 | .. option:: refill_buffers | |
1600 | ||
1601 | If this option is given, fio will refill the I/O buffers on every | |
72592780 SW |
1602 | submit. Only makes sense if :option:`zero_buffers` isn't specified, |
1603 | naturally. Defaults to being unset i.e., the buffer is only filled at | |
1604 | init time and the data in it is reused when possible but if any of | |
1605 | :option:`verify`, :option:`buffer_compress_percentage` or | |
1606 | :option:`dedupe_percentage` are enabled then `refill_buffers` is also | |
1607 | automatically enabled. | |
f80dba8d MT |
1608 | |
1609 | .. option:: scramble_buffers=bool | |
1610 | ||
1611 | If :option:`refill_buffers` is too costly and the target is using data | |
1612 | deduplication, then setting this option will slightly modify the I/O buffer | |
1613 | contents to defeat normal de-dupe attempts. This is not enough to defeat | |
1614 | more clever block compression attempts, but it will stop naive dedupe of | |
1615 | blocks. Default: true. | |
1616 | ||
1617 | .. option:: buffer_compress_percentage=int | |
1618 | ||
72592780 SW |
1619 | If this is set, then fio will attempt to provide I/O buffer content |
1620 | (on WRITEs) that compresses to the specified level. Fio does this by | |
1621 | providing a mix of random data followed by fixed pattern data. The | |
1622 | fixed pattern is either zeros, or the pattern specified by | |
1623 | :option:`buffer_pattern`. If the `buffer_pattern` option is used, it | |
1624 | might skew the compression ratio slightly. Setting | |
1625 | `buffer_compress_percentage` to a value other than 100 will also | |
1626 | enable :option:`refill_buffers` in order to reduce the likelihood that | |
1627 | adjacent blocks are so similar that they over compress when seen | |
1628 | together. See :option:`buffer_compress_chunk` for how to set a finer or | |
1629 | coarser granularity for the random/fixed data region. Defaults to unset | |
1630 | i.e., buffer data will not adhere to any compression level. | |
f80dba8d MT |
1631 | |
1632 | .. option:: buffer_compress_chunk=int | |
1633 | ||
72592780 SW |
1634 | This setting allows fio to manage how big the random/fixed data region |
1635 | is when using :option:`buffer_compress_percentage`. When | |
1636 | `buffer_compress_chunk` is set to some non-zero value smaller than the | |
1637 | block size, fio can repeat the random/fixed region throughout the I/O | |
1638 | buffer at the specified interval (which particularly useful when | |
1639 | bigger block sizes are used for a job). When set to 0, fio will use a | |
1640 | chunk size that matches the block size resulting in a single | |
1641 | random/fixed region within the I/O buffer. Defaults to 512. When the | |
1642 | unit is omitted, the value is interpreted in bytes. | |
f80dba8d MT |
1643 | |
1644 | .. option:: buffer_pattern=str | |
1645 | ||
a1554f65 SB |
1646 | If set, fio will fill the I/O buffers with this pattern or with the contents |
1647 | of a file. If not set, the contents of I/O buffers are defined by the other | |
1648 | options related to buffer contents. The setting can be any pattern of bytes, | |
1649 | and can be prefixed with 0x for hex values. It may also be a string, where | |
1650 | the string must then be wrapped with ``""``. Or it may also be a filename, | |
1651 | where the filename must be wrapped with ``''`` in which case the file is | |
1652 | opened and read. Note that not all the file contents will be read if that | |
1653 | would cause the buffers to overflow. So, for example:: | |
1654 | ||
1655 | buffer_pattern='filename' | |
1656 | ||
1657 | or:: | |
f80dba8d MT |
1658 | |
1659 | buffer_pattern="abcd" | |
1660 | ||
1661 | or:: | |
1662 | ||
1663 | buffer_pattern=-12 | |
1664 | ||
1665 | or:: | |
1666 | ||
1667 | buffer_pattern=0xdeadface | |
1668 | ||
1669 | Also you can combine everything together in any order:: | |
1670 | ||
a1554f65 | 1671 | buffer_pattern=0xdeadface"abcd"-12'filename' |
f80dba8d MT |
1672 | |
1673 | .. option:: dedupe_percentage=int | |
1674 | ||
1675 | If set, fio will generate this percentage of identical buffers when | |
1676 | writing. These buffers will be naturally dedupable. The contents of the | |
1677 | buffers depend on what other buffer compression settings have been set. It's | |
1678 | possible to have the individual buffers either fully compressible, or not at | |
72592780 SW |
1679 | all -- this option only controls the distribution of unique buffers. Setting |
1680 | this option will also enable :option:`refill_buffers` to prevent every buffer | |
1681 | being identical. | |
f80dba8d MT |
1682 | |
1683 | .. option:: invalidate=bool | |
1684 | ||
730bd7d9 SW |
1685 | Invalidate the buffer/page cache parts of the files to be used prior to |
1686 | starting I/O if the platform and file type support it. Defaults to true. | |
21c1b29e TK |
1687 | This will be ignored if :option:`pre_read` is also specified for the |
1688 | same job. | |
f80dba8d | 1689 | |
eb9f8d7f AF |
1690 | .. option:: sync=str |
1691 | ||
1692 | Whether, and what type, of synchronous I/O to use for writes. The allowed | |
1693 | values are: | |
1694 | ||
1695 | **none** | |
1696 | Do not use synchronous IO, the default. | |
1697 | ||
1698 | **0** | |
1699 | Same as **none**. | |
1700 | ||
1701 | **sync** | |
1702 | Use synchronous file IO. For the majority of I/O engines, | |
1703 | this means using O_SYNC. | |
1704 | ||
1705 | **1** | |
1706 | Same as **sync**. | |
1707 | ||
1708 | **dsync** | |
1709 | Use synchronous data IO. For the majority of I/O engines, | |
1710 | this means using O_DSYNC. | |
f80dba8d | 1711 | |
f80dba8d MT |
1712 | |
1713 | .. option:: iomem=str, mem=str | |
1714 | ||
1715 | Fio can use various types of memory as the I/O unit buffer. The allowed | |
1716 | values are: | |
1717 | ||
1718 | **malloc** | |
1719 | Use memory from :manpage:`malloc(3)` as the buffers. Default memory | |
1720 | type. | |
1721 | ||
1722 | **shm** | |
1723 | Use shared memory as the buffers. Allocated through | |
1724 | :manpage:`shmget(2)`. | |
1725 | ||
1726 | **shmhuge** | |
1727 | Same as shm, but use huge pages as backing. | |
1728 | ||
1729 | **mmap** | |
22413915 | 1730 | Use :manpage:`mmap(2)` to allocate buffers. May either be anonymous memory, or can |
f80dba8d MT |
1731 | be file backed if a filename is given after the option. The format |
1732 | is `mem=mmap:/path/to/file`. | |
1733 | ||
1734 | **mmaphuge** | |
1735 | Use a memory mapped huge file as the buffer backing. Append filename | |
1736 | after mmaphuge, ala `mem=mmaphuge:/hugetlbfs/file`. | |
1737 | ||
1738 | **mmapshared** | |
1739 | Same as mmap, but use a MMAP_SHARED mapping. | |
1740 | ||
03553853 YR |
1741 | **cudamalloc** |
1742 | Use GPU memory as the buffers for GPUDirect RDMA benchmark. | |
f50fbdda | 1743 | The :option:`ioengine` must be `rdma`. |
03553853 | 1744 | |
f80dba8d MT |
1745 | The area allocated is a function of the maximum allowed bs size for the job, |
1746 | multiplied by the I/O depth given. Note that for **shmhuge** and | |
1747 | **mmaphuge** to work, the system must have free huge pages allocated. This | |
1748 | can normally be checked and set by reading/writing | |
1749 | :file:`/proc/sys/vm/nr_hugepages` on a Linux system. Fio assumes a huge page | |
1750 | is 4MiB in size. So to calculate the number of huge pages you need for a | |
1751 | given job file, add up the I/O depth of all jobs (normally one unless | |
1752 | :option:`iodepth` is used) and multiply by the maximum bs set. Then divide | |
1753 | that number by the huge page size. You can see the size of the huge pages in | |
1754 | :file:`/proc/meminfo`. If no huge pages are allocated by having a non-zero | |
1755 | number in `nr_hugepages`, using **mmaphuge** or **shmhuge** will fail. Also | |
1756 | see :option:`hugepage-size`. | |
1757 | ||
1758 | **mmaphuge** also needs to have hugetlbfs mounted and the file location | |
1759 | should point there. So if it's mounted in :file:`/huge`, you would use | |
1760 | `mem=mmaphuge:/huge/somefile`. | |
1761 | ||
f50fbdda | 1762 | .. option:: iomem_align=int, mem_align=int |
f80dba8d MT |
1763 | |
1764 | This indicates the memory alignment of the I/O memory buffers. Note that | |
1765 | the given alignment is applied to the first I/O unit buffer, if using | |
1766 | :option:`iodepth` the alignment of the following buffers are given by the | |
1767 | :option:`bs` used. In other words, if using a :option:`bs` that is a | |
1768 | multiple of the page sized in the system, all buffers will be aligned to | |
1769 | this value. If using a :option:`bs` that is not page aligned, the alignment | |
1770 | of subsequent I/O memory buffers is the sum of the :option:`iomem_align` and | |
1771 | :option:`bs` used. | |
1772 | ||
1773 | .. option:: hugepage-size=int | |
1774 | ||
1775 | Defines the size of a huge page. Must at least be equal to the system | |
1776 | setting, see :file:`/proc/meminfo`. Defaults to 4MiB. Should probably | |
1777 | always be a multiple of megabytes, so using ``hugepage-size=Xm`` is the | |
1778 | preferred way to set this to avoid setting a non-pow-2 bad value. | |
1779 | ||
1780 | .. option:: lockmem=int | |
1781 | ||
1782 | Pin the specified amount of memory with :manpage:`mlock(2)`. Can be used to | |
1783 | simulate a smaller amount of memory. The amount specified is per worker. | |
1784 | ||
1785 | ||
1786 | I/O size | |
1787 | ~~~~~~~~ | |
1788 | ||
1789 | .. option:: size=int | |
1790 | ||
79591fa9 TK |
1791 | The total size of file I/O for each thread of this job. Fio will run until |
1792 | this many bytes has been transferred, unless runtime is limited by other options | |
1793 | (such as :option:`runtime`, for instance, or increased/decreased by :option:`io_size`). | |
1794 | Fio will divide this size between the available files determined by options | |
1795 | such as :option:`nrfiles`, :option:`filename`, unless :option:`filesize` is | |
1796 | specified by the job. If the result of division happens to be 0, the size is | |
c4aa2d08 | 1797 | set to the physical size of the given files or devices if they exist. |
79591fa9 | 1798 | If this option is not specified, fio will use the full size of the given |
f80dba8d MT |
1799 | files or devices. If the files do not exist, size must be given. It is also |
1800 | possible to give size as a percentage between 1 and 100. If ``size=20%`` is | |
1801 | given, fio will use 20% of the full size of the given files or devices. | |
9d25d068 SW |
1802 | Can be combined with :option:`offset` to constrain the start and end range |
1803 | that I/O will be done within. | |
f80dba8d MT |
1804 | |
1805 | .. option:: io_size=int, io_limit=int | |
1806 | ||
1807 | Normally fio operates within the region set by :option:`size`, which means | |
1808 | that the :option:`size` option sets both the region and size of I/O to be | |
1809 | performed. Sometimes that is not what you want. With this option, it is | |
1810 | possible to define just the amount of I/O that fio should do. For instance, | |
1811 | if :option:`size` is set to 20GiB and :option:`io_size` is set to 5GiB, fio | |
1812 | will perform I/O within the first 20GiB but exit when 5GiB have been | |
1813 | done. The opposite is also possible -- if :option:`size` is set to 20GiB, | |
1814 | and :option:`io_size` is set to 40GiB, then fio will do 40GiB of I/O within | |
1815 | the 0..20GiB region. | |
1816 | ||
7fdd97ca | 1817 | .. option:: filesize=irange(int) |
f80dba8d MT |
1818 | |
1819 | Individual file sizes. May be a range, in which case fio will select sizes | |
1820 | for files at random within the given range and limited to :option:`size` in | |
1821 | total (if that is given). If not given, each created file is the same size. | |
79591fa9 TK |
1822 | This option overrides :option:`size` in terms of file size, which means |
1823 | this value is used as a fixed size or possible range of each file. | |
f80dba8d MT |
1824 | |
1825 | .. option:: file_append=bool | |
1826 | ||
1827 | Perform I/O after the end of the file. Normally fio will operate within the | |
1828 | size of a file. If this option is set, then fio will append to the file | |
1829 | instead. This has identical behavior to setting :option:`offset` to the size | |
1830 | of a file. This option is ignored on non-regular files. | |
1831 | ||
1832 | .. option:: fill_device=bool, fill_fs=bool | |
1833 | ||
1834 | Sets size to something really large and waits for ENOSPC (no space left on | |
1835 | device) as the terminating condition. Only makes sense with sequential | |
1836 | write. For a read workload, the mount point will be filled first then I/O | |
1837 | started on the result. This option doesn't make sense if operating on a raw | |
1838 | device node, since the size of that is already known by the file system. | |
1839 | Additionally, writing beyond end-of-device will not return ENOSPC there. | |
1840 | ||
1841 | ||
1842 | I/O engine | |
1843 | ~~~~~~~~~~ | |
1844 | ||
1845 | .. option:: ioengine=str | |
1846 | ||
1847 | Defines how the job issues I/O to the file. The following types are defined: | |
1848 | ||
1849 | **sync** | |
1850 | Basic :manpage:`read(2)` or :manpage:`write(2)` | |
1851 | I/O. :manpage:`lseek(2)` is used to position the I/O location. | |
54227e6b | 1852 | See :option:`fsync` and :option:`fdatasync` for syncing write I/Os. |
f80dba8d MT |
1853 | |
1854 | **psync** | |
1855 | Basic :manpage:`pread(2)` or :manpage:`pwrite(2)` I/O. Default on | |
1856 | all supported operating systems except for Windows. | |
1857 | ||
1858 | **vsync** | |
1859 | Basic :manpage:`readv(2)` or :manpage:`writev(2)` I/O. Will emulate | |
c60ebc45 | 1860 | queuing by coalescing adjacent I/Os into a single submission. |
f80dba8d MT |
1861 | |
1862 | **pvsync** | |
1863 | Basic :manpage:`preadv(2)` or :manpage:`pwritev(2)` I/O. | |
1864 | ||
1865 | **pvsync2** | |
1866 | Basic :manpage:`preadv2(2)` or :manpage:`pwritev2(2)` I/O. | |
1867 | ||
029b42ac JA |
1868 | **io_uring** |
1869 | Fast Linux native asynchronous I/O. Supports async IO | |
1870 | for both direct and buffered IO. | |
1871 | This engine defines engine specific options. | |
1872 | ||
f80dba8d MT |
1873 | **libaio** |
1874 | Linux native asynchronous I/O. Note that Linux may only support | |
22413915 | 1875 | queued behavior with non-buffered I/O (set ``direct=1`` or |
f80dba8d MT |
1876 | ``buffered=0``). |
1877 | This engine defines engine specific options. | |
1878 | ||
1879 | **posixaio** | |
1880 | POSIX asynchronous I/O using :manpage:`aio_read(3)` and | |
1881 | :manpage:`aio_write(3)`. | |
1882 | ||
1883 | **solarisaio** | |
1884 | Solaris native asynchronous I/O. | |
1885 | ||
1886 | **windowsaio** | |
1887 | Windows native asynchronous I/O. Default on Windows. | |
1888 | ||
1889 | **mmap** | |
1890 | File is memory mapped with :manpage:`mmap(2)` and data copied | |
1891 | to/from using :manpage:`memcpy(3)`. | |
1892 | ||
1893 | **splice** | |
1894 | :manpage:`splice(2)` is used to transfer the data and | |
1895 | :manpage:`vmsplice(2)` to transfer data from user space to the | |
1896 | kernel. | |
1897 | ||
1898 | **sg** | |
1899 | SCSI generic sg v3 I/O. May either be synchronous using the SG_IO | |
1900 | ioctl, or if the target is an sg character device we use | |
1901 | :manpage:`read(2)` and :manpage:`write(2)` for asynchronous | |
f50fbdda | 1902 | I/O. Requires :option:`filename` option to specify either block or |
3740cfc8 | 1903 | character devices. This engine supports trim operations. |
52b81b7c | 1904 | The sg engine includes engine specific options. |
f80dba8d MT |
1905 | |
1906 | **null** | |
1907 | Doesn't transfer any data, just pretends to. This is mainly used to | |
1908 | exercise fio itself and for debugging/testing purposes. | |
1909 | ||
1910 | **net** | |
1911 | Transfer over the network to given ``host:port``. Depending on the | |
1912 | :option:`protocol` used, the :option:`hostname`, :option:`port`, | |
1913 | :option:`listen` and :option:`filename` options are used to specify | |
1914 | what sort of connection to make, while the :option:`protocol` option | |
1915 | determines which protocol will be used. This engine defines engine | |
1916 | specific options. | |
1917 | ||
1918 | **netsplice** | |
1919 | Like **net**, but uses :manpage:`splice(2)` and | |
1920 | :manpage:`vmsplice(2)` to map data and send/receive. | |
1921 | This engine defines engine specific options. | |
1922 | ||
1923 | **cpuio** | |
1924 | Doesn't transfer any data, but burns CPU cycles according to the | |
9de473a8 EV |
1925 | :option:`cpuload`, :option:`cpuchunks` and :option:`cpumode` options. |
1926 | Setting :option:`cpuload`\=85 will cause that job to do nothing but burn 85% | |
71aa48eb | 1927 | of the CPU. In case of SMP machines, use :option:`numjobs`\=<nr_of_cpu> |
f50fbdda | 1928 | to get desired CPU usage, as the cpuload only loads a |
f80dba8d MT |
1929 | single CPU at the desired rate. A job never finishes unless there is |
1930 | at least one non-cpuio job. | |
9de473a8 EV |
1931 | Setting :option:`cpumode`\=qsort replace the default noop instructions loop |
1932 | by a qsort algorithm to consume more energy. | |
f80dba8d | 1933 | |
f80dba8d MT |
1934 | **rdma** |
1935 | The RDMA I/O engine supports both RDMA memory semantics | |
1936 | (RDMA_WRITE/RDMA_READ) and channel semantics (Send/Recv) for the | |
609ac152 SB |
1937 | InfiniBand, RoCE and iWARP protocols. This engine defines engine |
1938 | specific options. | |
f80dba8d MT |
1939 | |
1940 | **falloc** | |
1941 | I/O engine that does regular fallocate to simulate data transfer as | |
1942 | fio ioengine. | |
1943 | ||
1944 | DDIR_READ | |
1945 | does fallocate(,mode = FALLOC_FL_KEEP_SIZE,). | |
1946 | ||
1947 | DDIR_WRITE | |
1948 | does fallocate(,mode = 0). | |
1949 | ||
1950 | DDIR_TRIM | |
1951 | does fallocate(,mode = FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE). | |
1952 | ||
761cd093 SW |
1953 | **ftruncate** |
1954 | I/O engine that sends :manpage:`ftruncate(2)` operations in response | |
1955 | to write (DDIR_WRITE) events. Each ftruncate issued sets the file's | |
f50fbdda | 1956 | size to the current block offset. :option:`blocksize` is ignored. |
761cd093 | 1957 | |
f80dba8d MT |
1958 | **e4defrag** |
1959 | I/O engine that does regular EXT4_IOC_MOVE_EXT ioctls to simulate | |
1960 | defragment activity in request to DDIR_WRITE event. | |
1961 | ||
f3f96717 IF |
1962 | **rados** |
1963 | I/O engine supporting direct access to Ceph Reliable Autonomic | |
1964 | Distributed Object Store (RADOS) via librados. This ioengine | |
1965 | defines engine specific options. | |
1966 | ||
f80dba8d MT |
1967 | **rbd** |
1968 | I/O engine supporting direct access to Ceph Rados Block Devices | |
1969 | (RBD) via librbd without the need to use the kernel rbd driver. This | |
1970 | ioengine defines engine specific options. | |
1971 | ||
c2f6a13d LMB |
1972 | **http** |
1973 | I/O engine supporting GET/PUT requests over HTTP(S) with libcurl to | |
1974 | a WebDAV or S3 endpoint. This ioengine defines engine specific options. | |
1975 | ||
1976 | This engine only supports direct IO of iodepth=1; you need to scale this | |
1977 | via numjobs. blocksize defines the size of the objects to be created. | |
1978 | ||
1979 | TRIM is translated to object deletion. | |
1980 | ||
f80dba8d | 1981 | **gfapi** |
ac8ca2af SW |
1982 | Using GlusterFS libgfapi sync interface to direct access to |
1983 | GlusterFS volumes without having to go through FUSE. This ioengine | |
f80dba8d MT |
1984 | defines engine specific options. |
1985 | ||
1986 | **gfapi_async** | |
ac8ca2af SW |
1987 | Using GlusterFS libgfapi async interface to direct access to |
1988 | GlusterFS volumes without having to go through FUSE. This ioengine | |
f80dba8d MT |
1989 | defines engine specific options. |
1990 | ||
1991 | **libhdfs** | |
f50fbdda | 1992 | Read and write through Hadoop (HDFS). The :option:`filename` option |
f80dba8d MT |
1993 | is used to specify host,port of the hdfs name-node to connect. This |
1994 | engine interprets offsets a little differently. In HDFS, files once | |
e25c0c91 SW |
1995 | created cannot be modified so random writes are not possible. To |
1996 | imitate this the libhdfs engine expects a bunch of small files to be | |
1997 | created over HDFS and will randomly pick a file from them | |
1998 | based on the offset generated by fio backend (see the example | |
f80dba8d | 1999 | job file to create such files, use ``rw=write`` option). Please |
e25c0c91 SW |
2000 | note, it may be necessary to set environment variables to work |
2001 | with HDFS/libhdfs properly. Each job uses its own connection to | |
f80dba8d MT |
2002 | HDFS. |
2003 | ||
2004 | **mtd** | |
2005 | Read, write and erase an MTD character device (e.g., | |
2006 | :file:`/dev/mtd0`). Discards are treated as erases. Depending on the | |
2007 | underlying device type, the I/O may have to go in a certain pattern, | |
2008 | e.g., on NAND, writing sequentially to erase blocks and discarding | |
c298ee71 | 2009 | before overwriting. The `trimwrite` mode works well for this |
f80dba8d MT |
2010 | constraint. |
2011 | ||
2012 | **pmemblk** | |
2013 | Read and write using filesystem DAX to a file on a filesystem | |
363a5f65 | 2014 | mounted with DAX on a persistent memory device through the PMDK |
f80dba8d MT |
2015 | libpmemblk library. |
2016 | ||
2017 | **dev-dax** | |
2018 | Read and write using device DAX to a persistent memory device (e.g., | |
363a5f65 | 2019 | /dev/dax0.0) through the PMDK libpmem library. |
f80dba8d MT |
2020 | |
2021 | **external** | |
2022 | Prefix to specify loading an external I/O engine object file. Append | |
c60ebc45 | 2023 | the engine filename, e.g. ``ioengine=external:/tmp/foo.o`` to load |
d243fd6d TK |
2024 | ioengine :file:`foo.o` in :file:`/tmp`. The path can be either |
2025 | absolute or relative. See :file:`engines/skeleton_external.c` for | |
2026 | details of writing an external I/O engine. | |
f80dba8d | 2027 | |
1216cc5a | 2028 | **filecreate** |
b71968b1 | 2029 | Simply create the files and do no I/O to them. You still need to |
1216cc5a | 2030 | set `filesize` so that all the accounting still occurs, but no |
b71968b1 | 2031 | actual I/O will be done other than creating the file. |
f80dba8d | 2032 | |
73ccd14e SF |
2033 | **filestat** |
2034 | Simply do stat() and do no I/O to the file. You need to set 'filesize' | |
2035 | and 'nrfiles', so that files will be created. | |
2036 | This engine is to measure file lookup and meta data access. | |
2037 | ||
ae0db592 TI |
2038 | **libpmem** |
2039 | Read and write using mmap I/O to a file on a filesystem | |
363a5f65 | 2040 | mounted with DAX on a persistent memory device through the PMDK |
ae0db592 TI |
2041 | libpmem library. |
2042 | ||
a40e7a59 GB |
2043 | **ime_psync** |
2044 | Synchronous read and write using DDN's Infinite Memory Engine (IME). | |
2045 | This engine is very basic and issues calls to IME whenever an IO is | |
2046 | queued. | |
2047 | ||
2048 | **ime_psyncv** | |
2049 | Synchronous read and write using DDN's Infinite Memory Engine (IME). | |
2050 | This engine uses iovecs and will try to stack as much IOs as possible | |
2051 | (if the IOs are "contiguous" and the IO depth is not exceeded) | |
2052 | before issuing a call to IME. | |
2053 | ||
2054 | **ime_aio** | |
2055 | Asynchronous read and write using DDN's Infinite Memory Engine (IME). | |
2056 | This engine will try to stack as much IOs as possible by creating | |
2057 | requests for IME. FIO will then decide when to commit these requests. | |
247ef2aa KZ |
2058 | **libiscsi** |
2059 | Read and write iscsi lun with libiscsi. | |
d643a1e2 | 2060 | **nbd** |
f2d6de5d | 2061 | Read and write a Network Block Device (NBD). |
a40e7a59 | 2062 | |
10756b2c BS |
2063 | **libcufile** |
2064 | I/O engine supporting libcufile synchronous access to nvidia-fs and a | |
2065 | GPUDirect Storage-supported filesystem. This engine performs | |
2066 | I/O without transferring buffers between user-space and the kernel, | |
2067 | unless :option:`verify` is set or :option:`cuda_io` is `posix`. | |
2068 | :option:`iomem` must not be `cudamalloc`. This ioengine defines | |
2069 | engine specific options. | |
2070 | ||
f80dba8d MT |
2071 | I/O engine specific parameters |
2072 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
2073 | ||
2074 | In addition, there are some parameters which are only valid when a specific | |
f50fbdda TK |
2075 | :option:`ioengine` is in use. These are used identically to normal parameters, |
2076 | with the caveat that when used on the command line, they must come after the | |
f80dba8d MT |
2077 | :option:`ioengine` that defines them is selected. |
2078 | ||
b2a432bf | 2079 | .. option:: cmdprio_percentage=int : [io_uring] [libaio] |
029b42ac | 2080 | |
b2a432bf PC |
2081 | Set the percentage of I/O that will be issued with higher priority by setting |
2082 | the priority bit. Non-read I/O is likely unaffected by ``cmdprio_percentage``. | |
2083 | This option cannot be used with the `prio` or `prioclass` options. For this | |
2084 | option to set the priority bit properly, NCQ priority must be supported and | |
7896180a VF |
2085 | enabled and :option:`direct`\=1 option must be used. fio must also be run as |
2086 | the root user. | |
029b42ac JA |
2087 | |
2088 | .. option:: fixedbufs : [io_uring] | |
2089 | ||
b2a432bf PC |
2090 | If fio is asked to do direct IO, then Linux will map pages for each |
2091 | IO call, and release them when IO is done. If this option is set, the | |
2092 | pages are pre-mapped before IO is started. This eliminates the need to | |
2093 | map and release for each IO. This is more efficient, and reduces the | |
2094 | IO latency as well. | |
2095 | ||
2096 | .. option:: hipri : [io_uring] | |
2097 | ||
2098 | If this option is set, fio will attempt to use polled IO completions. | |
2099 | Normal IO completions generate interrupts to signal the completion of | |
2100 | IO, polled completions do not. Hence they are require active reaping | |
2101 | by the application. The benefits are more efficient IO for high IOPS | |
2102 | scenarios, and lower latencies for low queue depth IO. | |
029b42ac | 2103 | |
5ffd5626 | 2104 | .. option:: registerfiles : [io_uring] |
2c870598 | 2105 | |
5ffd5626 JA |
2106 | With this option, fio registers the set of files being used with the |
2107 | kernel. This avoids the overhead of managing file counts in the kernel, | |
2108 | making the submission and completion part more lightweight. Required | |
2109 | for the below :option:`sqthread_poll` option. | |
2110 | ||
029b42ac JA |
2111 | .. option:: sqthread_poll : [io_uring] |
2112 | ||
2113 | Normally fio will submit IO by issuing a system call to notify the | |
2114 | kernel of available items in the SQ ring. If this option is set, the | |
2115 | act of submitting IO will be done by a polling thread in the kernel. | |
2116 | This frees up cycles for fio, at the cost of using more CPU in the | |
2117 | system. | |
2118 | ||
2119 | .. option:: sqthread_poll_cpu : [io_uring] | |
2120 | ||
2121 | When :option:`sqthread_poll` is set, this option provides a way to | |
2122 | define which CPU should be used for the polling thread. | |
2123 | ||
f80dba8d MT |
2124 | .. option:: userspace_reap : [libaio] |
2125 | ||
2126 | Normally, with the libaio engine in use, fio will use the | |
2127 | :manpage:`io_getevents(2)` system call to reap newly returned events. With | |
2128 | this flag turned on, the AIO ring will be read directly from user-space to | |
2129 | reap events. The reaping mode is only enabled when polling for a minimum of | |
c60ebc45 | 2130 | 0 events (e.g. when :option:`iodepth_batch_complete` `=0`). |
f80dba8d | 2131 | |
9d25d068 | 2132 | .. option:: hipri : [pvsync2] |
f80dba8d MT |
2133 | |
2134 | Set RWF_HIPRI on I/O, indicating to the kernel that it's of higher priority | |
2135 | than normal. | |
2136 | ||
a0679ce5 SB |
2137 | .. option:: hipri_percentage : [pvsync2] |
2138 | ||
f50fbdda | 2139 | When hipri is set this determines the probability of a pvsync2 I/O being high |
a0679ce5 SB |
2140 | priority. The default is 100%. |
2141 | ||
7d42e66e KK |
2142 | .. option:: nowait : [pvsync2] [libaio] [io_uring] |
2143 | ||
2144 | By default if a request cannot be executed immediately (e.g. resource starvation, | |
2145 | waiting on locks) it is queued and the initiating process will be blocked until | |
2146 | the required resource becomes free. | |
2147 | ||
2148 | This option sets the RWF_NOWAIT flag (supported from the 4.14 Linux kernel) and | |
2149 | the call will return instantly with EAGAIN or a partial result rather than waiting. | |
2150 | ||
2151 | It is useful to also use ignore_error=EAGAIN when using this option. | |
2152 | ||
2153 | Note: glibc 2.27, 2.28 have a bug in syscall wrappers preadv2, pwritev2. | |
2154 | They return EOPNOTSUP instead of EAGAIN. | |
2155 | ||
2156 | For cached I/O, using this option usually means a request operates only with | |
2157 | cached data. Currently the RWF_NOWAIT flag does not supported for cached write. | |
2158 | ||
2159 | For direct I/O, requests will only succeed if cache invalidation isn't required, | |
2160 | file blocks are fully allocated and the disk request could be issued immediately. | |
2161 | ||
f80dba8d MT |
2162 | .. option:: cpuload=int : [cpuio] |
2163 | ||
da19cdb4 TK |
2164 | Attempt to use the specified percentage of CPU cycles. This is a mandatory |
2165 | option when using cpuio I/O engine. | |
f80dba8d MT |
2166 | |
2167 | .. option:: cpuchunks=int : [cpuio] | |
2168 | ||
2169 | Split the load into cycles of the given time. In microseconds. | |
2170 | ||
2171 | .. option:: exit_on_io_done=bool : [cpuio] | |
2172 | ||
2173 | Detect when I/O threads are done, then exit. | |
2174 | ||
f80dba8d MT |
2175 | .. option:: namenode=str : [libhdfs] |
2176 | ||
22413915 | 2177 | The hostname or IP address of a HDFS cluster namenode to contact. |
f80dba8d MT |
2178 | |
2179 | .. option:: port=int | |
2180 | ||
f50fbdda TK |
2181 | [libhdfs] |
2182 | ||
2183 | The listening port of the HFDS cluster namenode. | |
2184 | ||
f80dba8d MT |
2185 | [netsplice], [net] |
2186 | ||
2187 | The TCP or UDP port to bind to or connect to. If this is used with | |
2188 | :option:`numjobs` to spawn multiple instances of the same job type, then | |
2189 | this will be the starting port number since fio will use a range of | |
2190 | ports. | |
2191 | ||
609ac152 SB |
2192 | [rdma] |
2193 | ||
2194 | The port to use for RDMA-CM communication. This should be the same value | |
2195 | on the client and the server side. | |
2196 | ||
2197 | .. option:: hostname=str : [netsplice] [net] [rdma] | |
f80dba8d | 2198 | |
609ac152 SB |
2199 | The hostname or IP address to use for TCP, UDP or RDMA-CM based I/O. If the job |
2200 | is a TCP listener or UDP reader, the hostname is not used and must be omitted | |
f50fbdda | 2201 | unless it is a valid UDP multicast address. |
f80dba8d MT |
2202 | |
2203 | .. option:: interface=str : [netsplice] [net] | |
2204 | ||
2205 | The IP address of the network interface used to send or receive UDP | |
2206 | multicast. | |
2207 | ||
2208 | .. option:: ttl=int : [netsplice] [net] | |
2209 | ||
2210 | Time-to-live value for outgoing UDP multicast packets. Default: 1. | |
2211 | ||
2212 | .. option:: nodelay=bool : [netsplice] [net] | |
2213 | ||
2214 | Set TCP_NODELAY on TCP connections. | |
2215 | ||
f50fbdda | 2216 | .. option:: protocol=str, proto=str : [netsplice] [net] |
f80dba8d MT |
2217 | |
2218 | The network protocol to use. Accepted values are: | |
2219 | ||
2220 | **tcp** | |
2221 | Transmission control protocol. | |
2222 | **tcpv6** | |
2223 | Transmission control protocol V6. | |
2224 | **udp** | |
2225 | User datagram protocol. | |
2226 | **udpv6** | |
2227 | User datagram protocol V6. | |
2228 | **unix** | |
2229 | UNIX domain socket. | |
2230 | ||
2231 | When the protocol is TCP or UDP, the port must also be given, as well as the | |
2232 | hostname if the job is a TCP listener or UDP reader. For unix sockets, the | |
f50fbdda | 2233 | normal :option:`filename` option should be used and the port is invalid. |
f80dba8d | 2234 | |
e9184ec1 | 2235 | .. option:: listen : [netsplice] [net] |
f80dba8d MT |
2236 | |
2237 | For TCP network connections, tell fio to listen for incoming connections | |
2238 | rather than initiating an outgoing connection. The :option:`hostname` must | |
2239 | be omitted if this option is used. | |
2240 | ||
e9184ec1 | 2241 | .. option:: pingpong : [netsplice] [net] |
f80dba8d MT |
2242 | |
2243 | Normally a network writer will just continue writing data, and a network | |
2244 | reader will just consume packages. If ``pingpong=1`` is set, a writer will | |
2245 | send its normal payload to the reader, then wait for the reader to send the | |
2246 | same payload back. This allows fio to measure network latencies. The | |
2247 | submission and completion latencies then measure local time spent sending or | |
2248 | receiving, and the completion latency measures how long it took for the | |
2249 | other end to receive and send back. For UDP multicast traffic | |
2250 | ``pingpong=1`` should only be set for a single reader when multiple readers | |
2251 | are listening to the same address. | |
2252 | ||
e9184ec1 | 2253 | .. option:: window_size : [netsplice] [net] |
f80dba8d MT |
2254 | |
2255 | Set the desired socket buffer size for the connection. | |
2256 | ||
e9184ec1 | 2257 | .. option:: mss : [netsplice] [net] |
f80dba8d MT |
2258 | |
2259 | Set the TCP maximum segment size (TCP_MAXSEG). | |
2260 | ||
2261 | .. option:: donorname=str : [e4defrag] | |
2262 | ||
730bd7d9 | 2263 | File will be used as a block donor (swap extents between files). |
f80dba8d MT |
2264 | |
2265 | .. option:: inplace=int : [e4defrag] | |
2266 | ||
2267 | Configure donor file blocks allocation strategy: | |
2268 | ||
2269 | **0** | |
2270 | Default. Preallocate donor's file on init. | |
2271 | **1** | |
2b455dbf | 2272 | Allocate space immediately inside defragment event, and free right |
f80dba8d MT |
2273 | after event. |
2274 | ||
f3f96717 | 2275 | .. option:: clustername=str : [rbd,rados] |
f80dba8d MT |
2276 | |
2277 | Specifies the name of the Ceph cluster. | |
2278 | ||
2279 | .. option:: rbdname=str : [rbd] | |
2280 | ||
2281 | Specifies the name of the RBD. | |
2282 | ||
f3f96717 | 2283 | .. option:: pool=str : [rbd,rados] |
f80dba8d | 2284 | |
f3f96717 | 2285 | Specifies the name of the Ceph pool containing RBD or RADOS data. |
f80dba8d | 2286 | |
f3f96717 | 2287 | .. option:: clientname=str : [rbd,rados] |
f80dba8d MT |
2288 | |
2289 | Specifies the username (without the 'client.' prefix) used to access the | |
2290 | Ceph cluster. If the *clustername* is specified, the *clientname* shall be | |
2291 | the full *type.id* string. If no type. prefix is given, fio will add | |
2292 | 'client.' by default. | |
2293 | ||
f3f96717 IF |
2294 | .. option:: busy_poll=bool : [rbd,rados] |
2295 | ||
2296 | Poll store instead of waiting for completion. Usually this provides better | |
2297 | throughput at cost of higher(up to 100%) CPU utilization. | |
2298 | ||
f80dba8d MT |
2299 | .. option:: skip_bad=bool : [mtd] |
2300 | ||
2301 | Skip operations against known bad blocks. | |
2302 | ||
2303 | .. option:: hdfsdirectory : [libhdfs] | |
2304 | ||
2305 | libhdfs will create chunk in this HDFS directory. | |
2306 | ||
2307 | .. option:: chunk_size : [libhdfs] | |
2308 | ||
2b455dbf | 2309 | The size of the chunk to use for each file. |
f80dba8d | 2310 | |
609ac152 SB |
2311 | .. option:: verb=str : [rdma] |
2312 | ||
2313 | The RDMA verb to use on this side of the RDMA ioengine connection. Valid | |
2314 | values are write, read, send and recv. These correspond to the equivalent | |
2315 | RDMA verbs (e.g. write = rdma_write etc.). Note that this only needs to be | |
2316 | specified on the client side of the connection. See the examples folder. | |
2317 | ||
2318 | .. option:: bindname=str : [rdma] | |
2319 | ||
2320 | The name to use to bind the local RDMA-CM connection to a local RDMA device. | |
2321 | This could be a hostname or an IPv4 or IPv6 address. On the server side this | |
2322 | will be passed into the rdma_bind_addr() function and on the client site it | |
2323 | will be used in the rdma_resolve_add() function. This can be useful when | |
2324 | multiple paths exist between the client and the server or in certain loopback | |
2325 | configurations. | |
f80dba8d | 2326 | |
93a13ba5 | 2327 | .. option:: stat_type=str : [filestat] |
c446eff0 | 2328 | |
93a13ba5 TK |
2329 | Specify stat system call type to measure lookup/getattr performance. |
2330 | Default is **stat** for :manpage:`stat(2)`. | |
c446eff0 | 2331 | |
52b81b7c KD |
2332 | .. option:: readfua=bool : [sg] |
2333 | ||
2334 | With readfua option set to 1, read operations include | |
2335 | the force unit access (fua) flag. Default is 0. | |
2336 | ||
2337 | .. option:: writefua=bool : [sg] | |
2338 | ||
2339 | With writefua option set to 1, write operations include | |
2340 | the force unit access (fua) flag. Default is 0. | |
2341 | ||
2c3a9150 | 2342 | .. option:: sg_write_mode=str : [sg] |
3740cfc8 | 2343 | |
2c3a9150 VF |
2344 | Specify the type of write commands to issue. This option can take three values: |
2345 | ||
2346 | **write** | |
2347 | This is the default where write opcodes are issued as usual. | |
2348 | **verify** | |
2349 | Issue WRITE AND VERIFY commands. The BYTCHK bit is set to 0. This | |
2350 | directs the device to carry out a medium verification with no data | |
2351 | comparison. The writefua option is ignored with this selection. | |
2352 | **same** | |
2353 | Issue WRITE SAME commands. This transfers a single block to the device | |
2354 | and writes this same block of data to a contiguous sequence of LBAs | |
2355 | beginning at the specified offset. fio's block size parameter specifies | |
2356 | the amount of data written with each command. However, the amount of data | |
2357 | actually transferred to the device is equal to the device's block | |
2358 | (sector) size. For a device with 512 byte sectors, blocksize=8k will | |
2359 | write 16 sectors with each command. fio will still generate 8k of data | |
2360 | for each command but only the first 512 bytes will be used and | |
2361 | transferred to the device. The writefua option is ignored with this | |
2362 | selection. | |
52b81b7c | 2363 | |
e493ceae JA |
2364 | .. option:: hipri : [sg] |
2365 | ||
2366 | If this option is set, fio will attempt to use polled IO completions. | |
2367 | This will have a similar effect as (io_uring)hipri. Only SCSI READ and | |
2368 | WRITE commands will have the SGV4_FLAG_HIPRI set (not UNMAP (trim) nor | |
2369 | VERIFY). Older versions of the Linux sg driver that do not support | |
2370 | hipri will simply ignore this flag and do normal IO. The Linux SCSI | |
2371 | Low Level Driver (LLD) that "owns" the device also needs to support | |
2372 | hipri (also known as iopoll and mq_poll). The MegaRAID driver is an | |
2373 | example of a SCSI LLD. Default: clear (0) which does normal | |
2374 | (interrupted based) IO. | |
2375 | ||
c2f6a13d LMB |
2376 | .. option:: http_host=str : [http] |
2377 | ||
2378 | Hostname to connect to. For S3, this could be the bucket hostname. | |
2379 | Default is **localhost** | |
2380 | ||
2381 | .. option:: http_user=str : [http] | |
2382 | ||
2383 | Username for HTTP authentication. | |
2384 | ||
2385 | .. option:: http_pass=str : [http] | |
2386 | ||
2387 | Password for HTTP authentication. | |
2388 | ||
09fd2966 | 2389 | .. option:: https=str : [http] |
c2f6a13d | 2390 | |
09fd2966 LMB |
2391 | Enable HTTPS instead of http. *on* enables HTTPS; *insecure* |
2392 | will enable HTTPS, but disable SSL peer verification (use with | |
2393 | caution!). Default is **off** | |
c2f6a13d | 2394 | |
09fd2966 | 2395 | .. option:: http_mode=str : [http] |
c2f6a13d | 2396 | |
09fd2966 LMB |
2397 | Which HTTP access mode to use: *webdav*, *swift*, or *s3*. |
2398 | Default is **webdav** | |
c2f6a13d LMB |
2399 | |
2400 | .. option:: http_s3_region=str : [http] | |
2401 | ||
2402 | The S3 region/zone string. | |
2403 | Default is **us-east-1** | |
2404 | ||
2405 | .. option:: http_s3_key=str : [http] | |
2406 | ||
2407 | The S3 secret key. | |
2408 | ||
2409 | .. option:: http_s3_keyid=str : [http] | |
2410 | ||
2411 | The S3 key/access id. | |
2412 | ||
09fd2966 LMB |
2413 | .. option:: http_swift_auth_token=str : [http] |
2414 | ||
2415 | The Swift auth token. See the example configuration file on how | |
2416 | to retrieve this. | |
2417 | ||
c2f6a13d LMB |
2418 | .. option:: http_verbose=int : [http] |
2419 | ||
2420 | Enable verbose requests from libcurl. Useful for debugging. 1 | |
2421 | turns on verbose logging from libcurl, 2 additionally enables | |
2422 | HTTP IO tracing. Default is **0** | |
2423 | ||
f2d6de5d RJ |
2424 | .. option:: uri=str : [nbd] |
2425 | ||
2426 | Specify the NBD URI of the server to test. The string | |
2427 | is a standard NBD URI | |
2428 | (see https://github.com/NetworkBlockDevice/nbd/tree/master/doc). | |
2429 | Example URIs: nbd://localhost:10809 | |
2430 | nbd+unix:///?socket=/tmp/socket | |
2431 | nbds://tlshost/exportname | |
2432 | ||
10756b2c BS |
2433 | .. option:: gpu_dev_ids=str : [libcufile] |
2434 | ||
2435 | Specify the GPU IDs to use with CUDA. This is a colon-separated list of | |
2436 | int. GPUs are assigned to workers roundrobin. Default is 0. | |
2437 | ||
2438 | .. option:: cuda_io=str : [libcufile] | |
2439 | ||
2440 | Specify the type of I/O to use with CUDA. Default is **cufile**. | |
2441 | ||
2442 | **cufile** | |
2443 | Use libcufile and nvidia-fs. This option performs I/O directly | |
2444 | between a GPUDirect Storage filesystem and GPU buffers, | |
2445 | avoiding use of a bounce buffer. If :option:`verify` is set, | |
2446 | cudaMemcpy is used to copy verificaton data between RAM and GPU. | |
2447 | Verification data is copied from RAM to GPU before a write | |
2448 | and from GPU to RAM after a read. :option:`direct` must be 1. | |
2449 | **posix** | |
2450 | Use POSIX to perform I/O with a RAM buffer, and use cudaMemcpy | |
2451 | to transfer data between RAM and the GPUs. Data is copied from | |
2452 | GPU to RAM before a write and copied from RAM to GPU after a | |
2453 | read. :option:`verify` does not affect use of cudaMemcpy. | |
2454 | ||
f80dba8d MT |
2455 | I/O depth |
2456 | ~~~~~~~~~ | |
2457 | ||
2458 | .. option:: iodepth=int | |
2459 | ||
2460 | Number of I/O units to keep in flight against the file. Note that | |
2461 | increasing *iodepth* beyond 1 will not affect synchronous ioengines (except | |
c60ebc45 | 2462 | for small degrees when :option:`verify_async` is in use). Even async |
f80dba8d MT |
2463 | engines may impose OS restrictions causing the desired depth not to be |
2464 | achieved. This may happen on Linux when using libaio and not setting | |
9207a0cb | 2465 | :option:`direct`\=1, since buffered I/O is not async on that OS. Keep an |
f80dba8d MT |
2466 | eye on the I/O depth distribution in the fio output to verify that the |
2467 | achieved depth is as expected. Default: 1. | |
2468 | ||
2469 | .. option:: iodepth_batch_submit=int, iodepth_batch=int | |
2470 | ||
2471 | This defines how many pieces of I/O to submit at once. It defaults to 1 | |
2472 | which means that we submit each I/O as soon as it is available, but can be | |
2473 | raised to submit bigger batches of I/O at the time. If it is set to 0 the | |
2474 | :option:`iodepth` value will be used. | |
2475 | ||
2476 | .. option:: iodepth_batch_complete_min=int, iodepth_batch_complete=int | |
2477 | ||
2478 | This defines how many pieces of I/O to retrieve at once. It defaults to 1 | |
2479 | which means that we'll ask for a minimum of 1 I/O in the retrieval process | |
2480 | from the kernel. The I/O retrieval will go on until we hit the limit set by | |
2481 | :option:`iodepth_low`. If this variable is set to 0, then fio will always | |
2482 | check for completed events before queuing more I/O. This helps reduce I/O | |
2483 | latency, at the cost of more retrieval system calls. | |
2484 | ||
2485 | .. option:: iodepth_batch_complete_max=int | |
2486 | ||
2487 | This defines maximum pieces of I/O to retrieve at once. This variable should | |
9207a0cb | 2488 | be used along with :option:`iodepth_batch_complete_min`\=int variable, |
f80dba8d | 2489 | specifying the range of min and max amount of I/O which should be |
730bd7d9 | 2490 | retrieved. By default it is equal to the :option:`iodepth_batch_complete_min` |
f80dba8d MT |
2491 | value. |
2492 | ||
2493 | Example #1:: | |
2494 | ||
2495 | iodepth_batch_complete_min=1 | |
2496 | iodepth_batch_complete_max=<iodepth> | |
2497 | ||
2498 | which means that we will retrieve at least 1 I/O and up to the whole | |
2499 | submitted queue depth. If none of I/O has been completed yet, we will wait. | |
2500 | ||
2501 | Example #2:: | |
2502 | ||
2503 | iodepth_batch_complete_min=0 | |
2504 | iodepth_batch_complete_max=<iodepth> | |
2505 | ||
2506 | which means that we can retrieve up to the whole submitted queue depth, but | |
2507 | if none of I/O has been completed yet, we will NOT wait and immediately exit | |
2508 | the system call. In this example we simply do polling. | |
2509 | ||
2510 | .. option:: iodepth_low=int | |
2511 | ||
2512 | The low water mark indicating when to start filling the queue | |
2513 | again. Defaults to the same as :option:`iodepth`, meaning that fio will | |
2514 | attempt to keep the queue full at all times. If :option:`iodepth` is set to | |
c60ebc45 | 2515 | e.g. 16 and *iodepth_low* is set to 4, then after fio has filled the queue of |
f80dba8d MT |
2516 | 16 requests, it will let the depth drain down to 4 before starting to fill |
2517 | it again. | |
2518 | ||
997b5680 SW |
2519 | .. option:: serialize_overlap=bool |
2520 | ||
2521 | Serialize in-flight I/Os that might otherwise cause or suffer from data races. | |
2522 | When two or more I/Os are submitted simultaneously, there is no guarantee that | |
2523 | the I/Os will be processed or completed in the submitted order. Further, if | |
2524 | two or more of those I/Os are writes, any overlapping region between them can | |
2525 | become indeterminate/undefined on certain storage. These issues can cause | |
2526 | verification to fail erratically when at least one of the racing I/Os is | |
2527 | changing data and the overlapping region has a non-zero size. Setting | |
2528 | ``serialize_overlap`` tells fio to avoid provoking this behavior by explicitly | |
2529 | serializing in-flight I/Os that have a non-zero overlap. Note that setting | |
ee21ebee | 2530 | this option can reduce both performance and the :option:`iodepth` achieved. |
3d6a6f04 VF |
2531 | |
2532 | This option only applies to I/Os issued for a single job except when it is | |
a02ec45a | 2533 | enabled along with :option:`io_submit_mode`\=offload. In offload mode, fio |
3d6a6f04 | 2534 | will check for overlap among all I/Os submitted by offload jobs with :option:`serialize_overlap` |
307f2246 | 2535 | enabled. |
3d6a6f04 VF |
2536 | |
2537 | Default: false. | |
997b5680 | 2538 | |
f80dba8d MT |
2539 | .. option:: io_submit_mode=str |
2540 | ||
2541 | This option controls how fio submits the I/O to the I/O engine. The default | |
2542 | is `inline`, which means that the fio job threads submit and reap I/O | |
2543 | directly. If set to `offload`, the job threads will offload I/O submission | |
2544 | to a dedicated pool of I/O threads. This requires some coordination and thus | |
2545 | has a bit of extra overhead, especially for lower queue depth I/O where it | |
2546 | can increase latencies. The benefit is that fio can manage submission rates | |
2547 | independently of the device completion rates. This avoids skewed latency | |
730bd7d9 | 2548 | reporting if I/O gets backed up on the device side (the coordinated omission |
abfd235a JA |
2549 | problem). Note that this option cannot reliably be used with async IO |
2550 | engines. | |
f80dba8d MT |
2551 | |
2552 | ||
2553 | I/O rate | |
2554 | ~~~~~~~~ | |
2555 | ||
a881438b | 2556 | .. option:: thinktime=time |
f80dba8d | 2557 | |
f75ede1d SW |
2558 | Stall the job for the specified period of time after an I/O has completed before issuing the |
2559 | next. May be used to simulate processing being done by an application. | |
947e0fe0 | 2560 | When the unit is omitted, the value is interpreted in microseconds. See |
f80dba8d MT |
2561 | :option:`thinktime_blocks` and :option:`thinktime_spin`. |
2562 | ||
a881438b | 2563 | .. option:: thinktime_spin=time |
f80dba8d MT |
2564 | |
2565 | Only valid if :option:`thinktime` is set - pretend to spend CPU time doing | |
2566 | something with the data received, before falling back to sleeping for the | |
f75ede1d | 2567 | rest of the period specified by :option:`thinktime`. When the unit is |
947e0fe0 | 2568 | omitted, the value is interpreted in microseconds. |
f80dba8d MT |
2569 | |
2570 | .. option:: thinktime_blocks=int | |
2571 | ||
2572 | Only valid if :option:`thinktime` is set - control how many blocks to issue, | |
f50fbdda TK |
2573 | before waiting :option:`thinktime` usecs. If not set, defaults to 1 which will make |
2574 | fio wait :option:`thinktime` usecs after every block. This effectively makes any | |
f80dba8d | 2575 | queue depth setting redundant, since no more than 1 I/O will be queued |
f50fbdda | 2576 | before we have to complete it and do our :option:`thinktime`. In other words, this |
f80dba8d | 2577 | setting effectively caps the queue depth if the latter is larger. |
71bfa161 | 2578 | |
33f42c20 HQ |
2579 | .. option:: thinktime_blocks_type=str |
2580 | ||
2581 | Only valid if :option:`thinktime` is set - control how :option:`thinktime_blocks` | |
2582 | triggers. The default is `complete`, which triggers thinktime when fio completes | |
2583 | :option:`thinktime_blocks` blocks. If this is set to `issue`, then the trigger happens | |
2584 | at the issue side. | |
2585 | ||
f80dba8d | 2586 | .. option:: rate=int[,int][,int] |
71bfa161 | 2587 | |
f80dba8d MT |
2588 | Cap the bandwidth used by this job. The number is in bytes/sec, the normal |
2589 | suffix rules apply. Comma-separated values may be specified for reads, | |
2590 | writes, and trims as described in :option:`blocksize`. | |
71bfa161 | 2591 | |
b25b3464 SW |
2592 | For example, using `rate=1m,500k` would limit reads to 1MiB/sec and writes to |
2593 | 500KiB/sec. Capping only reads or writes can be done with `rate=,500k` or | |
2594 | `rate=500k,` where the former will only limit writes (to 500KiB/sec) and the | |
2595 | latter will only limit reads. | |
2596 | ||
f80dba8d | 2597 | .. option:: rate_min=int[,int][,int] |
71bfa161 | 2598 | |
f80dba8d MT |
2599 | Tell fio to do whatever it can to maintain at least this bandwidth. Failing |
2600 | to meet this requirement will cause the job to exit. Comma-separated values | |
2601 | may be specified for reads, writes, and trims as described in | |
2602 | :option:`blocksize`. | |
71bfa161 | 2603 | |
f80dba8d | 2604 | .. option:: rate_iops=int[,int][,int] |
71bfa161 | 2605 | |
f80dba8d MT |
2606 | Cap the bandwidth to this number of IOPS. Basically the same as |
2607 | :option:`rate`, just specified independently of bandwidth. If the job is | |
2608 | given a block size range instead of a fixed value, the smallest block size | |
2609 | is used as the metric. Comma-separated values may be specified for reads, | |
2610 | writes, and trims as described in :option:`blocksize`. | |
71bfa161 | 2611 | |
f80dba8d | 2612 | .. option:: rate_iops_min=int[,int][,int] |
71bfa161 | 2613 | |
f80dba8d MT |
2614 | If fio doesn't meet this rate of I/O, it will cause the job to exit. |
2615 | Comma-separated values may be specified for reads, writes, and trims as | |
2616 | described in :option:`blocksize`. | |
71bfa161 | 2617 | |
f80dba8d | 2618 | .. option:: rate_process=str |
66c098b8 | 2619 | |
f80dba8d MT |
2620 | This option controls how fio manages rated I/O submissions. The default is |
2621 | `linear`, which submits I/O in a linear fashion with fixed delays between | |
c60ebc45 | 2622 | I/Os that gets adjusted based on I/O completion rates. If this is set to |
f80dba8d MT |
2623 | `poisson`, fio will submit I/O based on a more real world random request |
2624 | flow, known as the Poisson process | |
2625 | (https://en.wikipedia.org/wiki/Poisson_point_process). The lambda will be | |
2626 | 10^6 / IOPS for the given workload. | |
71bfa161 | 2627 | |
1a9bf814 JA |
2628 | .. option:: rate_ignore_thinktime=bool |
2629 | ||
2630 | By default, fio will attempt to catch up to the specified rate setting, | |
2631 | if any kind of thinktime setting was used. If this option is set, then | |
2632 | fio will ignore the thinktime and continue doing IO at the specified | |
2633 | rate, instead of entering a catch-up mode after thinktime is done. | |
2634 | ||
71bfa161 | 2635 | |
f80dba8d MT |
2636 | I/O latency |
2637 | ~~~~~~~~~~~ | |
71bfa161 | 2638 | |
a881438b | 2639 | .. option:: latency_target=time |
71bfa161 | 2640 | |
f80dba8d | 2641 | If set, fio will attempt to find the max performance point that the given |
f75ede1d | 2642 | workload will run at while maintaining a latency below this target. When |
947e0fe0 | 2643 | the unit is omitted, the value is interpreted in microseconds. See |
f75ede1d | 2644 | :option:`latency_window` and :option:`latency_percentile`. |
71bfa161 | 2645 | |
a881438b | 2646 | .. option:: latency_window=time |
71bfa161 | 2647 | |
f80dba8d | 2648 | Used with :option:`latency_target` to specify the sample window that the job |
f75ede1d | 2649 | is run at varying queue depths to test the performance. When the unit is |
947e0fe0 | 2650 | omitted, the value is interpreted in microseconds. |
b4692828 | 2651 | |
f80dba8d | 2652 | .. option:: latency_percentile=float |
71bfa161 | 2653 | |
c60ebc45 | 2654 | The percentage of I/Os that must fall within the criteria specified by |
f80dba8d | 2655 | :option:`latency_target` and :option:`latency_window`. If not set, this |
c60ebc45 | 2656 | defaults to 100.0, meaning that all I/Os must be equal or below to the value |
f80dba8d | 2657 | set by :option:`latency_target`. |
71bfa161 | 2658 | |
e1bcd541 SL |
2659 | .. option:: latency_run=bool |
2660 | ||
2661 | Used with :option:`latency_target`. If false (default), fio will find | |
2662 | the highest queue depth that meets :option:`latency_target` and exit. If | |
2663 | true, fio will continue running and try to meet :option:`latency_target` | |
2664 | by adjusting queue depth. | |
2665 | ||
a881438b | 2666 | .. option:: max_latency=time |
71bfa161 | 2667 | |
f75ede1d | 2668 | If set, fio will exit the job with an ETIMEDOUT error if it exceeds this |
947e0fe0 | 2669 | maximum latency. When the unit is omitted, the value is interpreted in |
f75ede1d | 2670 | microseconds. |
71bfa161 | 2671 | |
f80dba8d | 2672 | .. option:: rate_cycle=int |
71bfa161 | 2673 | |
f80dba8d | 2674 | Average bandwidth for :option:`rate` and :option:`rate_min` over this number |
a47b697c | 2675 | of milliseconds. Defaults to 1000. |
71bfa161 | 2676 | |
71bfa161 | 2677 | |
f80dba8d MT |
2678 | I/O replay |
2679 | ~~~~~~~~~~ | |
71bfa161 | 2680 | |
f80dba8d | 2681 | .. option:: write_iolog=str |
c2b1e753 | 2682 | |
f80dba8d MT |
2683 | Write the issued I/O patterns to the specified file. See |
2684 | :option:`read_iolog`. Specify a separate file for each job, otherwise the | |
2685 | iologs will be interspersed and the file may be corrupt. | |
c2b1e753 | 2686 | |
f80dba8d | 2687 | .. option:: read_iolog=str |
71bfa161 | 2688 | |
22413915 | 2689 | Open an iolog with the specified filename and replay the I/O patterns it |
f80dba8d MT |
2690 | contains. This can be used to store a workload and replay it sometime |
2691 | later. The iolog given may also be a blktrace binary file, which allows fio | |
2692 | to replay a workload captured by :command:`blktrace`. See | |
2693 | :manpage:`blktrace(8)` for how to capture such logging data. For blktrace | |
2694 | replay, the file needs to be turned into a blkparse binary data file first | |
2695 | (``blkparse <device> -o /dev/null -d file_for_fio.bin``). | |
78439a18 JA |
2696 | You can specify a number of files by separating the names with a ':' |
2697 | character. See the :option:`filename` option for information on how to | |
3b803fe1 | 2698 | escape ':' characters within the file names. These files will |
78439a18 | 2699 | be sequentially assigned to job clones created by :option:`numjobs`. |
d19c04d1 | 2700 | '-' is a reserved name, meaning read from stdin, notably if |
2701 | :option:`filename` is set to '-' which means stdin as well, then | |
2702 | this flag can't be set to '-'. | |
71bfa161 | 2703 | |
77be374d AK |
2704 | .. option:: read_iolog_chunked=bool |
2705 | ||
2706 | Determines how iolog is read. If false(default) entire :option:`read_iolog` | |
2707 | will be read at once. If selected true, input from iolog will be read | |
2708 | gradually. Useful when iolog is very large, or it is generated. | |
2709 | ||
b9921d1a DZ |
2710 | .. option:: merge_blktrace_file=str |
2711 | ||
2712 | When specified, rather than replaying the logs passed to :option:`read_iolog`, | |
2713 | the logs go through a merge phase which aggregates them into a single | |
2714 | blktrace. The resulting file is then passed on as the :option:`read_iolog` | |
2715 | parameter. The intention here is to make the order of events consistent. | |
2716 | This limits the influence of the scheduler compared to replaying multiple | |
2717 | blktraces via concurrent jobs. | |
2718 | ||
87a48ada DZ |
2719 | .. option:: merge_blktrace_scalars=float_list |
2720 | ||
2721 | This is a percentage based option that is index paired with the list of | |
2722 | files passed to :option:`read_iolog`. When merging is performed, scale | |
2723 | the time of each event by the corresponding amount. For example, | |
2724 | ``--merge_blktrace_scalars="50:100"`` runs the first trace in halftime | |
2725 | and the second trace in realtime. This knob is separately tunable from | |
2726 | :option:`replay_time_scale` which scales the trace during runtime and | |
2727 | does not change the output of the merge unlike this option. | |
2728 | ||
55bfd8c8 DZ |
2729 | .. option:: merge_blktrace_iters=float_list |
2730 | ||
2731 | This is a whole number option that is index paired with the list of files | |
2732 | passed to :option:`read_iolog`. When merging is performed, run each trace | |
2733 | for the specified number of iterations. For example, | |
2734 | ``--merge_blktrace_iters="2:1"`` runs the first trace for two iterations | |
2735 | and the second trace for one iteration. | |
2736 | ||
589e88b7 | 2737 | .. option:: replay_no_stall=bool |
71bfa161 | 2738 | |
f80dba8d | 2739 | When replaying I/O with :option:`read_iolog` the default behavior is to |
22413915 | 2740 | attempt to respect the timestamps within the log and replay them with the |
f80dba8d MT |
2741 | appropriate delay between IOPS. By setting this variable fio will not |
2742 | respect the timestamps and attempt to replay them as fast as possible while | |
2743 | still respecting ordering. The result is the same I/O pattern to a given | |
2744 | device, but different timings. | |
71bfa161 | 2745 | |
6dd7fa77 JA |
2746 | .. option:: replay_time_scale=int |
2747 | ||
2748 | When replaying I/O with :option:`read_iolog`, fio will honor the | |
2749 | original timing in the trace. With this option, it's possible to scale | |
2750 | the time. It's a percentage option, if set to 50 it means run at 50% | |
2751 | the original IO rate in the trace. If set to 200, run at twice the | |
2752 | original IO rate. Defaults to 100. | |
2753 | ||
f80dba8d | 2754 | .. option:: replay_redirect=str |
b4692828 | 2755 | |
f80dba8d MT |
2756 | While replaying I/O patterns using :option:`read_iolog` the default behavior |
2757 | is to replay the IOPS onto the major/minor device that each IOP was recorded | |
2758 | from. This is sometimes undesirable because on a different machine those | |
2759 | major/minor numbers can map to a different device. Changing hardware on the | |
2760 | same system can also result in a different major/minor mapping. | |
730bd7d9 | 2761 | ``replay_redirect`` causes all I/Os to be replayed onto the single specified |
f80dba8d | 2762 | device regardless of the device it was recorded |
9207a0cb | 2763 | from. i.e. :option:`replay_redirect`\= :file:`/dev/sdc` would cause all I/O |
f80dba8d MT |
2764 | in the blktrace or iolog to be replayed onto :file:`/dev/sdc`. This means |
2765 | multiple devices will be replayed onto a single device, if the trace | |
2766 | contains multiple devices. If you want multiple devices to be replayed | |
2767 | concurrently to multiple redirected devices you must blkparse your trace | |
2768 | into separate traces and replay them with independent fio invocations. | |
2769 | Unfortunately this also breaks the strict time ordering between multiple | |
2770 | device accesses. | |
71bfa161 | 2771 | |
f80dba8d | 2772 | .. option:: replay_align=int |
74929ac2 | 2773 | |
350a535d DZ |
2774 | Force alignment of the byte offsets in a trace to this value. The value |
2775 | must be a power of 2. | |
3c54bc46 | 2776 | |
f80dba8d | 2777 | .. option:: replay_scale=int |
3c54bc46 | 2778 | |
350a535d DZ |
2779 | Scale byte offsets down by this factor when replaying traces. Should most |
2780 | likely use :option:`replay_align` as well. | |
3c54bc46 | 2781 | |
38f68906 JA |
2782 | .. option:: replay_skip=str |
2783 | ||
2784 | Sometimes it's useful to skip certain IO types in a replay trace. | |
2785 | This could be, for instance, eliminating the writes in the trace. | |
2786 | Or not replaying the trims/discards, if you are redirecting to | |
2787 | a device that doesn't support them. This option takes a comma | |
2788 | separated list of read, write, trim, sync. | |
2789 | ||
3c54bc46 | 2790 | |
f80dba8d MT |
2791 | Threads, processes and job synchronization |
2792 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
3c54bc46 | 2793 | |
f80dba8d | 2794 | .. option:: thread |
3c54bc46 | 2795 | |
730bd7d9 SW |
2796 | Fio defaults to creating jobs by using fork, however if this option is |
2797 | given, fio will create jobs by using POSIX Threads' function | |
2798 | :manpage:`pthread_create(3)` to create threads instead. | |
71bfa161 | 2799 | |
f80dba8d | 2800 | .. option:: wait_for=str |
74929ac2 | 2801 | |
730bd7d9 SW |
2802 | If set, the current job won't be started until all workers of the specified |
2803 | waitee job are done. | |
74929ac2 | 2804 | |
f80dba8d MT |
2805 | ``wait_for`` operates on the job name basis, so there are a few |
2806 | limitations. First, the waitee must be defined prior to the waiter job | |
2807 | (meaning no forward references). Second, if a job is being referenced as a | |
2808 | waitee, it must have a unique name (no duplicate waitees). | |
74929ac2 | 2809 | |
f80dba8d | 2810 | .. option:: nice=int |
892a6ffc | 2811 | |
f80dba8d | 2812 | Run the job with the given nice value. See man :manpage:`nice(2)`. |
892a6ffc | 2813 | |
f80dba8d MT |
2814 | On Windows, values less than -15 set the process class to "High"; -1 through |
2815 | -15 set "Above Normal"; 1 through 15 "Below Normal"; and above 15 "Idle" | |
2816 | priority class. | |
74929ac2 | 2817 | |
f80dba8d | 2818 | .. option:: prio=int |
71bfa161 | 2819 | |
f80dba8d MT |
2820 | Set the I/O priority value of this job. Linux limits us to a positive value |
2821 | between 0 and 7, with 0 being the highest. See man | |
2822 | :manpage:`ionice(1)`. Refer to an appropriate manpage for other operating | |
b2a432bf PC |
2823 | systems since meaning of priority may differ. For per-command priority |
2824 | setting, see I/O engine specific `cmdprio_percentage` and `hipri_percentage` | |
2825 | options. | |
71bfa161 | 2826 | |
f80dba8d | 2827 | .. option:: prioclass=int |
d59aa780 | 2828 | |
b2a432bf PC |
2829 | Set the I/O priority class. See man :manpage:`ionice(1)`. For per-command |
2830 | priority setting, see I/O engine specific `cmdprio_percentage` and | |
2831 | `hipri_percentage` options. | |
d59aa780 | 2832 | |
f80dba8d | 2833 | .. option:: cpus_allowed=str |
6d500c2e | 2834 | |
730bd7d9 | 2835 | Controls the same options as :option:`cpumask`, but accepts a textual |
b570e037 SW |
2836 | specification of the permitted CPUs instead and CPUs are indexed from 0. So |
2837 | to use CPUs 0 and 5 you would specify ``cpus_allowed=0,5``. This option also | |
2838 | allows a range of CPUs to be specified -- say you wanted a binding to CPUs | |
2839 | 0, 5, and 8 to 15, you would set ``cpus_allowed=0,5,8-15``. | |
2840 | ||
2841 | On Windows, when ``cpus_allowed`` is unset only CPUs from fio's current | |
2842 | processor group will be used and affinity settings are inherited from the | |
2843 | system. An fio build configured to target Windows 7 makes options that set | |
2844 | CPUs processor group aware and values will set both the processor group | |
2845 | and a CPU from within that group. For example, on a system where processor | |
2846 | group 0 has 40 CPUs and processor group 1 has 32 CPUs, ``cpus_allowed`` | |
2847 | values between 0 and 39 will bind CPUs from processor group 0 and | |
2848 | ``cpus_allowed`` values between 40 and 71 will bind CPUs from processor | |
2849 | group 1. When using ``cpus_allowed_policy=shared`` all CPUs specified by a | |
2850 | single ``cpus_allowed`` option must be from the same processor group. For | |
2851 | Windows fio builds not built for Windows 7, CPUs will only be selected from | |
2852 | (and be relative to) whatever processor group fio happens to be running in | |
2853 | and CPUs from other processor groups cannot be used. | |
6d500c2e | 2854 | |
f80dba8d | 2855 | .. option:: cpus_allowed_policy=str |
6d500c2e | 2856 | |
f80dba8d | 2857 | Set the policy of how fio distributes the CPUs specified by |
730bd7d9 | 2858 | :option:`cpus_allowed` or :option:`cpumask`. Two policies are supported: |
6d500c2e | 2859 | |
f80dba8d MT |
2860 | **shared** |
2861 | All jobs will share the CPU set specified. | |
2862 | **split** | |
2863 | Each job will get a unique CPU from the CPU set. | |
6d500c2e | 2864 | |
22413915 | 2865 | **shared** is the default behavior, if the option isn't specified. If |
b21fc93f | 2866 | **split** is specified, then fio will assign one cpu per job. If not |
f80dba8d MT |
2867 | enough CPUs are given for the jobs listed, then fio will roundrobin the CPUs |
2868 | in the set. | |
6d500c2e | 2869 | |
b570e037 SW |
2870 | .. option:: cpumask=int |
2871 | ||
2872 | Set the CPU affinity of this job. The parameter given is a bit mask of | |
2873 | allowed CPUs the job may run on. So if you want the allowed CPUs to be 1 | |
2874 | and 5, you would pass the decimal value of (1 << 1 | 1 << 5), or 34. See man | |
2875 | :manpage:`sched_setaffinity(2)`. This may not work on all supported | |
2876 | operating systems or kernel versions. This option doesn't work well for a | |
2877 | higher CPU count than what you can store in an integer mask, so it can only | |
2878 | control cpus 1-32. For boxes with larger CPU counts, use | |
2879 | :option:`cpus_allowed`. | |
2880 | ||
f80dba8d | 2881 | .. option:: numa_cpu_nodes=str |
6d500c2e | 2882 | |
f80dba8d MT |
2883 | Set this job running on specified NUMA nodes' CPUs. The arguments allow |
2884 | comma delimited list of cpu numbers, A-B ranges, or `all`. Note, to enable | |
ac8ca2af | 2885 | NUMA options support, fio must be built on a system with libnuma-dev(el) |
f80dba8d | 2886 | installed. |
61b9861d | 2887 | |
f80dba8d | 2888 | .. option:: numa_mem_policy=str |
61b9861d | 2889 | |
f80dba8d MT |
2890 | Set this job's memory policy and corresponding NUMA nodes. Format of the |
2891 | arguments:: | |
5c94b008 | 2892 | |
f80dba8d | 2893 | <mode>[:<nodelist>] |
ce35b1ec | 2894 | |
804c0839 | 2895 | ``mode`` is one of the following memory policies: ``default``, ``prefer``, |
730bd7d9 SW |
2896 | ``bind``, ``interleave`` or ``local``. For ``default`` and ``local`` memory |
2897 | policies, no node needs to be specified. For ``prefer``, only one node is | |
2898 | allowed. For ``bind`` and ``interleave`` the ``nodelist`` may be as | |
2899 | follows: a comma delimited list of numbers, A-B ranges, or `all`. | |
71bfa161 | 2900 | |
f80dba8d | 2901 | .. option:: cgroup=str |
390b1537 | 2902 | |
f80dba8d MT |
2903 | Add job to this control group. If it doesn't exist, it will be created. The |
2904 | system must have a mounted cgroup blkio mount point for this to work. If | |
2905 | your system doesn't have it mounted, you can do so with:: | |
5af1c6f3 | 2906 | |
f80dba8d | 2907 | # mount -t cgroup -o blkio none /cgroup |
5af1c6f3 | 2908 | |
f80dba8d | 2909 | .. option:: cgroup_weight=int |
5af1c6f3 | 2910 | |
f80dba8d MT |
2911 | Set the weight of the cgroup to this value. See the documentation that comes |
2912 | with the kernel, allowed values are in the range of 100..1000. | |
a086c257 | 2913 | |
f80dba8d | 2914 | .. option:: cgroup_nodelete=bool |
8c07860d | 2915 | |
f80dba8d MT |
2916 | Normally fio will delete the cgroups it has created after the job |
2917 | completion. To override this behavior and to leave cgroups around after the | |
2918 | job completion, set ``cgroup_nodelete=1``. This can be useful if one wants | |
2919 | to inspect various cgroup files after job completion. Default: false. | |
8c07860d | 2920 | |
f80dba8d | 2921 | .. option:: flow_id=int |
8c07860d | 2922 | |
f80dba8d MT |
2923 | The ID of the flow. If not specified, it defaults to being a global |
2924 | flow. See :option:`flow`. | |
1907dbc6 | 2925 | |
f80dba8d | 2926 | .. option:: flow=int |
71bfa161 | 2927 | |
f80dba8d MT |
2928 | Weight in token-based flow control. If this value is used, then there is a |
2929 | 'flow counter' which is used to regulate the proportion of activity between | |
2930 | two or more jobs. Fio attempts to keep this flow counter near zero. The | |
2931 | ``flow`` parameter stands for how much should be added or subtracted to the | |
2932 | flow counter on each iteration of the main I/O loop. That is, if one job has | |
2933 | ``flow=8`` and another job has ``flow=-1``, then there will be a roughly 1:8 | |
2934 | ratio in how much one runs vs the other. | |
71bfa161 | 2935 | |
f80dba8d | 2936 | .. option:: flow_sleep=int |
82407585 | 2937 | |
d4e74fda DB |
2938 | The period of time, in microseconds, to wait after the flow counter |
2939 | has exceeded its proportion before retrying operations. | |
82407585 | 2940 | |
f80dba8d | 2941 | .. option:: stonewall, wait_for_previous |
82407585 | 2942 | |
f80dba8d MT |
2943 | Wait for preceding jobs in the job file to exit, before starting this |
2944 | one. Can be used to insert serialization points in the job file. A stone | |
2945 | wall also implies starting a new reporting group, see | |
2946 | :option:`group_reporting`. | |
2947 | ||
2948 | .. option:: exitall | |
2949 | ||
64402a8a HW |
2950 | By default, fio will continue running all other jobs when one job finishes. |
2951 | Sometimes this is not the desired action. Setting ``exitall`` will instead | |
2952 | make fio terminate all jobs in the same group, as soon as one job of that | |
2953 | group finishes. | |
2954 | ||
2955 | .. option:: exit_what | |
2956 | ||
2957 | By default, fio will continue running all other jobs when one job finishes. | |
2958 | Sometimes this is not the desired action. Setting ``exit_all`` will | |
2959 | instead make fio terminate all jobs in the same group. The option | |
2960 | ``exit_what`` allows to control which jobs get terminated when ``exitall`` is | |
2961 | enabled. The default is ``group`` and does not change the behaviour of | |
2962 | ``exitall``. The setting ``all`` terminates all jobs. The setting ``stonewall`` | |
2963 | terminates all currently running jobs across all groups and continues execution | |
2964 | with the next stonewalled group. | |
f80dba8d MT |
2965 | |
2966 | .. option:: exec_prerun=str | |
2967 | ||
2968 | Before running this job, issue the command specified through | |
2969 | :manpage:`system(3)`. Output is redirected in a file called | |
2970 | :file:`jobname.prerun.txt`. | |
2971 | ||
2972 | .. option:: exec_postrun=str | |
2973 | ||
2974 | After the job completes, issue the command specified though | |
2975 | :manpage:`system(3)`. Output is redirected in a file called | |
2976 | :file:`jobname.postrun.txt`. | |
2977 | ||
2978 | .. option:: uid=int | |
2979 | ||
2980 | Instead of running as the invoking user, set the user ID to this value | |
2981 | before the thread/process does any work. | |
2982 | ||
2983 | .. option:: gid=int | |
2984 | ||
2985 | Set group ID, see :option:`uid`. | |
2986 | ||
2987 | ||
2988 | Verification | |
2989 | ~~~~~~~~~~~~ | |
2990 | ||
2991 | .. option:: verify_only | |
2992 | ||
2993 | Do not perform specified workload, only verify data still matches previous | |
2994 | invocation of this workload. This option allows one to check data multiple | |
2995 | times at a later date without overwriting it. This option makes sense only | |
2996 | for workloads that write data, and does not support workloads with the | |
2997 | :option:`time_based` option set. | |
2998 | ||
2999 | .. option:: do_verify=bool | |
3000 | ||
3001 | Run the verify phase after a write phase. Only valid if :option:`verify` is | |
3002 | set. Default: true. | |
3003 | ||
3004 | .. option:: verify=str | |
3005 | ||
3006 | If writing to a file, fio can verify the file contents after each iteration | |
3007 | of the job. Each verification method also implies verification of special | |
3008 | header, which is written to the beginning of each block. This header also | |
3009 | includes meta information, like offset of the block, block number, timestamp | |
3010 | when block was written, etc. :option:`verify` can be combined with | |
3011 | :option:`verify_pattern` option. The allowed values are: | |
3012 | ||
3013 | **md5** | |
3014 | Use an md5 sum of the data area and store it in the header of | |
3015 | each block. | |
3016 | ||
3017 | **crc64** | |
3018 | Use an experimental crc64 sum of the data area and store it in the | |
3019 | header of each block. | |
3020 | ||
3021 | **crc32c** | |
a5896300 SW |
3022 | Use a crc32c sum of the data area and store it in the header of |
3023 | each block. This will automatically use hardware acceleration | |
3024 | (e.g. SSE4.2 on an x86 or CRC crypto extensions on ARM64) but will | |
3025 | fall back to software crc32c if none is found. Generally the | |
804c0839 | 3026 | fastest checksum fio supports when hardware accelerated. |
f80dba8d MT |
3027 | |
3028 | **crc32c-intel** | |
a5896300 | 3029 | Synonym for crc32c. |
f80dba8d MT |
3030 | |
3031 | **crc32** | |
3032 | Use a crc32 sum of the data area and store it in the header of each | |
3033 | block. | |
3034 | ||
3035 | **crc16** | |
3036 | Use a crc16 sum of the data area and store it in the header of each | |
3037 | block. | |
3038 | ||
3039 | **crc7** | |
3040 | Use a crc7 sum of the data area and store it in the header of each | |
3041 | block. | |
3042 | ||
3043 | **xxhash** | |
3044 | Use xxhash as the checksum function. Generally the fastest software | |
3045 | checksum that fio supports. | |
3046 | ||
3047 | **sha512** | |
3048 | Use sha512 as the checksum function. | |
3049 | ||
3050 | **sha256** | |
3051 | Use sha256 as the checksum function. | |
3052 | ||
3053 | **sha1** | |
3054 | Use optimized sha1 as the checksum function. | |
82407585 | 3055 | |
ae3a5acc JA |
3056 | **sha3-224** |
3057 | Use optimized sha3-224 as the checksum function. | |
3058 | ||
3059 | **sha3-256** | |
3060 | Use optimized sha3-256 as the checksum function. | |
3061 | ||
3062 | **sha3-384** | |
3063 | Use optimized sha3-384 as the checksum function. | |
3064 | ||
3065 | **sha3-512** | |
3066 | Use optimized sha3-512 as the checksum function. | |
3067 | ||
f80dba8d MT |
3068 | **meta** |
3069 | This option is deprecated, since now meta information is included in | |
3070 | generic verification header and meta verification happens by | |
3071 | default. For detailed information see the description of the | |
3072 | :option:`verify` setting. This option is kept because of | |
3073 | compatibility's sake with old configurations. Do not use it. | |
3074 | ||
3075 | **pattern** | |
3076 | Verify a strict pattern. Normally fio includes a header with some | |
3077 | basic information and checksumming, but if this option is set, only | |
3078 | the specific pattern set with :option:`verify_pattern` is verified. | |
3079 | ||
3080 | **null** | |
3081 | Only pretend to verify. Useful for testing internals with | |
9207a0cb | 3082 | :option:`ioengine`\=null, not for much else. |
f80dba8d MT |
3083 | |
3084 | This option can be used for repeated burn-in tests of a system to make sure | |
3085 | that the written data is also correctly read back. If the data direction | |
3086 | given is a read or random read, fio will assume that it should verify a | |
3087 | previously written file. If the data direction includes any form of write, | |
3088 | the verify will be of the newly written data. | |
3089 | ||
47e6a6e5 SW |
3090 | To avoid false verification errors, do not use the norandommap option when |
3091 | verifying data with async I/O engines and I/O depths > 1. Or use the | |
3092 | norandommap and the lfsr random generator together to avoid writing to the | |
3093 | same offset with muliple outstanding I/Os. | |
3094 | ||
f80dba8d MT |
3095 | .. option:: verify_offset=int |
3096 | ||
3097 | Swap the verification header with data somewhere else in the block before | |
3098 | writing. It is swapped back before verifying. | |
3099 | ||
3100 | .. option:: verify_interval=int | |
3101 | ||
3102 | Write the verification header at a finer granularity than the | |
3103 | :option:`blocksize`. It will be written for chunks the size of | |
3104 | ``verify_interval``. :option:`blocksize` should divide this evenly. | |
3105 | ||
3106 | .. option:: verify_pattern=str | |
3107 | ||
3108 | If set, fio will fill the I/O buffers with this pattern. Fio defaults to | |
3109 | filling with totally random bytes, but sometimes it's interesting to fill | |
3110 | with a known pattern for I/O verification purposes. Depending on the width | |
730bd7d9 | 3111 | of the pattern, fio will fill 1/2/3/4 bytes of the buffer at the time (it can |
f80dba8d MT |
3112 | be either a decimal or a hex number). The ``verify_pattern`` if larger than |
3113 | a 32-bit quantity has to be a hex number that starts with either "0x" or | |
3114 | "0X". Use with :option:`verify`. Also, ``verify_pattern`` supports %o | |
3115 | format, which means that for each block offset will be written and then | |
3116 | verified back, e.g.:: | |
61b9861d RP |
3117 | |
3118 | verify_pattern=%o | |
3119 | ||
f80dba8d MT |
3120 | Or use combination of everything:: |
3121 | ||
61b9861d | 3122 | verify_pattern=0xff%o"abcd"-12 |
e28218f3 | 3123 | |
f80dba8d MT |
3124 | .. option:: verify_fatal=bool |
3125 | ||
3126 | Normally fio will keep checking the entire contents before quitting on a | |
3127 | block verification failure. If this option is set, fio will exit the job on | |
3128 | the first observed failure. Default: false. | |
3129 | ||
3130 | .. option:: verify_dump=bool | |
3131 | ||
3132 | If set, dump the contents of both the original data block and the data block | |
3133 | we read off disk to files. This allows later analysis to inspect just what | |
3134 | kind of data corruption occurred. Off by default. | |
3135 | ||
3136 | .. option:: verify_async=int | |
3137 | ||
3138 | Fio will normally verify I/O inline from the submitting thread. This option | |
3139 | takes an integer describing how many async offload threads to create for I/O | |
3140 | verification instead, causing fio to offload the duty of verifying I/O | |
3141 | contents to one or more separate threads. If using this offload option, even | |
3142 | sync I/O engines can benefit from using an :option:`iodepth` setting higher | |
3143 | than 1, as it allows them to have I/O in flight while verifies are running. | |
d7e6ea1c | 3144 | Defaults to 0 async threads, i.e. verification is not asynchronous. |
f80dba8d MT |
3145 | |
3146 | .. option:: verify_async_cpus=str | |
3147 | ||
3148 | Tell fio to set the given CPU affinity on the async I/O verification | |
3149 | threads. See :option:`cpus_allowed` for the format used. | |
3150 | ||
3151 | .. option:: verify_backlog=int | |
3152 | ||
3153 | Fio will normally verify the written contents of a job that utilizes verify | |
3154 | once that job has completed. In other words, everything is written then | |
3155 | everything is read back and verified. You may want to verify continually | |
3156 | instead for a variety of reasons. Fio stores the meta data associated with | |
3157 | an I/O block in memory, so for large verify workloads, quite a bit of memory | |
3158 | would be used up holding this meta data. If this option is enabled, fio will | |
3159 | write only N blocks before verifying these blocks. | |
3160 | ||
3161 | .. option:: verify_backlog_batch=int | |
3162 | ||
3163 | Control how many blocks fio will verify if :option:`verify_backlog` is | |
3164 | set. If not set, will default to the value of :option:`verify_backlog` | |
3165 | (meaning the entire queue is read back and verified). If | |
3166 | ``verify_backlog_batch`` is less than :option:`verify_backlog` then not all | |
3167 | blocks will be verified, if ``verify_backlog_batch`` is larger than | |
3168 | :option:`verify_backlog`, some blocks will be verified more than once. | |
3169 | ||
3170 | .. option:: verify_state_save=bool | |
3171 | ||
3172 | When a job exits during the write phase of a verify workload, save its | |
3173 | current state. This allows fio to replay up until that point, if the verify | |
3174 | state is loaded for the verify read phase. The format of the filename is, | |
3175 | roughly:: | |
3176 | ||
f50fbdda | 3177 | <type>-<jobname>-<jobindex>-verify.state. |
f80dba8d MT |
3178 | |
3179 | <type> is "local" for a local run, "sock" for a client/server socket | |
3180 | connection, and "ip" (192.168.0.1, for instance) for a networked | |
d7e6ea1c | 3181 | client/server connection. Defaults to true. |
f80dba8d MT |
3182 | |
3183 | .. option:: verify_state_load=bool | |
3184 | ||
3185 | If a verify termination trigger was used, fio stores the current write state | |
3186 | of each thread. This can be used at verification time so that fio knows how | |
3187 | far it should verify. Without this information, fio will run a full | |
a47b697c SW |
3188 | verification pass, according to the settings in the job file used. Default |
3189 | false. | |
f80dba8d MT |
3190 | |
3191 | .. option:: trim_percentage=int | |
3192 | ||
3193 | Number of verify blocks to discard/trim. | |
3194 | ||
3195 | .. option:: trim_verify_zero=bool | |
3196 | ||
22413915 | 3197 | Verify that trim/discarded blocks are returned as zeros. |
f80dba8d MT |
3198 | |
3199 | .. option:: trim_backlog=int | |
3200 | ||
5cfd1e9a | 3201 | Trim after this number of blocks are written. |
f80dba8d MT |
3202 | |
3203 | .. option:: trim_backlog_batch=int | |
3204 | ||
3205 | Trim this number of I/O blocks. | |
3206 | ||
3207 | .. option:: experimental_verify=bool | |
3208 | ||
3209 | Enable experimental verification. | |
3210 | ||
f80dba8d MT |
3211 | Steady state |
3212 | ~~~~~~~~~~~~ | |
3213 | ||
3214 | .. option:: steadystate=str:float, ss=str:float | |
3215 | ||
3216 | Define the criterion and limit for assessing steady state performance. The | |
3217 | first parameter designates the criterion whereas the second parameter sets | |
3218 | the threshold. When the criterion falls below the threshold for the | |
3219 | specified duration, the job will stop. For example, `iops_slope:0.1%` will | |
3220 | direct fio to terminate the job when the least squares regression slope | |
3221 | falls below 0.1% of the mean IOPS. If :option:`group_reporting` is enabled | |
3222 | this will apply to all jobs in the group. Below is the list of available | |
3223 | steady state assessment criteria. All assessments are carried out using only | |
3224 | data from the rolling collection window. Threshold limits can be expressed | |
3225 | as a fixed value or as a percentage of the mean in the collection window. | |
3226 | ||
1cb049d9 VF |
3227 | When using this feature, most jobs should include the :option:`time_based` |
3228 | and :option:`runtime` options or the :option:`loops` option so that fio does not | |
3229 | stop running after it has covered the full size of the specified file(s) or device(s). | |
3230 | ||
f80dba8d MT |
3231 | **iops** |
3232 | Collect IOPS data. Stop the job if all individual IOPS measurements | |
3233 | are within the specified limit of the mean IOPS (e.g., ``iops:2`` | |
3234 | means that all individual IOPS values must be within 2 of the mean, | |
3235 | whereas ``iops:0.2%`` means that all individual IOPS values must be | |
3236 | within 0.2% of the mean IOPS to terminate the job). | |
3237 | ||
3238 | **iops_slope** | |
3239 | Collect IOPS data and calculate the least squares regression | |
3240 | slope. Stop the job if the slope falls below the specified limit. | |
3241 | ||
3242 | **bw** | |
3243 | Collect bandwidth data. Stop the job if all individual bandwidth | |
3244 | measurements are within the specified limit of the mean bandwidth. | |
3245 | ||
3246 | **bw_slope** | |
3247 | Collect bandwidth data and calculate the least squares regression | |
3248 | slope. Stop the job if the slope falls below the specified limit. | |
3249 | ||
3250 | .. option:: steadystate_duration=time, ss_dur=time | |
3251 | ||
3252 | A rolling window of this duration will be used to judge whether steady state | |
3253 | has been reached. Data will be collected once per second. The default is 0 | |
f75ede1d | 3254 | which disables steady state detection. When the unit is omitted, the |
947e0fe0 | 3255 | value is interpreted in seconds. |
f80dba8d MT |
3256 | |
3257 | .. option:: steadystate_ramp_time=time, ss_ramp=time | |
3258 | ||
3259 | Allow the job to run for the specified duration before beginning data | |
3260 | collection for checking the steady state job termination criterion. The | |
947e0fe0 | 3261 | default is 0. When the unit is omitted, the value is interpreted in seconds. |
f80dba8d MT |
3262 | |
3263 | ||
3264 | Measurements and reporting | |
3265 | ~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
3266 | ||
3267 | .. option:: per_job_logs=bool | |
3268 | ||
3269 | If set, this generates bw/clat/iops log with per file private filenames. If | |
3270 | not set, jobs with identical names will share the log filename. Default: | |
3271 | true. | |
3272 | ||
3273 | .. option:: group_reporting | |
3274 | ||
3275 | It may sometimes be interesting to display statistics for groups of jobs as | |
3276 | a whole instead of for each individual job. This is especially true if | |
3277 | :option:`numjobs` is used; looking at individual thread/process output | |
3278 | quickly becomes unwieldy. To see the final report per-group instead of | |
3279 | per-job, use :option:`group_reporting`. Jobs in a file will be part of the | |
3280 | same reporting group, unless if separated by a :option:`stonewall`, or by | |
3281 | using :option:`new_group`. | |
3282 | ||
3283 | .. option:: new_group | |
3284 | ||
3285 | Start a new reporting group. See: :option:`group_reporting`. If not given, | |
3286 | all jobs in a file will be part of the same reporting group, unless | |
3287 | separated by a :option:`stonewall`. | |
3288 | ||
589e88b7 | 3289 | .. option:: stats=bool |
8243be59 JA |
3290 | |
3291 | By default, fio collects and shows final output results for all jobs | |
3292 | that run. If this option is set to 0, then fio will ignore it in | |
3293 | the final stat output. | |
3294 | ||
f80dba8d MT |
3295 | .. option:: write_bw_log=str |
3296 | ||
3297 | If given, write a bandwidth log for this job. Can be used to store data of | |
074f0817 | 3298 | the bandwidth of the jobs in their lifetime. |
f80dba8d | 3299 | |
074f0817 SW |
3300 | If no str argument is given, the default filename of |
3301 | :file:`jobname_type.x.log` is used. Even when the argument is given, fio | |
3302 | will still append the type of log. So if one specifies:: | |
3303 | ||
3304 | write_bw_log=foo | |
f80dba8d | 3305 | |
074f0817 SW |
3306 | The actual log name will be :file:`foo_bw.x.log` where `x` is the index |
3307 | of the job (`1..N`, where `N` is the number of jobs). If | |
3308 | :option:`per_job_logs` is false, then the filename will not include the | |
3309 | `.x` job index. | |
e3cedca7 | 3310 | |
074f0817 SW |
3311 | The included :command:`fio_generate_plots` script uses :command:`gnuplot` to turn these |
3312 | text files into nice graphs. See `Log File Formats`_ for how data is | |
3313 | structured within the file. | |
3314 | ||
3315 | .. option:: write_lat_log=str | |
e3cedca7 | 3316 | |
074f0817 | 3317 | Same as :option:`write_bw_log`, except this option creates I/O |
77b7e675 SW |
3318 | submission (e.g., :file:`name_slat.x.log`), completion (e.g., |
3319 | :file:`name_clat.x.log`), and total (e.g., :file:`name_lat.x.log`) | |
074f0817 SW |
3320 | latency files instead. See :option:`write_bw_log` for details about |
3321 | the filename format and `Log File Formats`_ for how data is structured | |
3322 | within the files. | |
be4ecfdf | 3323 | |
f80dba8d | 3324 | .. option:: write_hist_log=str |
06842027 | 3325 | |
074f0817 | 3326 | Same as :option:`write_bw_log` but writes an I/O completion latency |
77b7e675 | 3327 | histogram file (e.g., :file:`name_hist.x.log`) instead. Note that this |
074f0817 SW |
3328 | file will be empty unless :option:`log_hist_msec` has also been set. |
3329 | See :option:`write_bw_log` for details about the filename format and | |
3330 | `Log File Formats`_ for how data is structured within the file. | |
06842027 | 3331 | |
f80dba8d | 3332 | .. option:: write_iops_log=str |
06842027 | 3333 | |
074f0817 | 3334 | Same as :option:`write_bw_log`, but writes an IOPS file (e.g. |
15417073 SW |
3335 | :file:`name_iops.x.log`) instead. Because fio defaults to individual |
3336 | I/O logging, the value entry in the IOPS log will be 1 unless windowed | |
3337 | logging (see :option:`log_avg_msec`) has been enabled. See | |
3338 | :option:`write_bw_log` for details about the filename format and `Log | |
3339 | File Formats`_ for how data is structured within the file. | |
06842027 | 3340 | |
f80dba8d | 3341 | .. option:: log_avg_msec=int |
06842027 | 3342 | |
f80dba8d MT |
3343 | By default, fio will log an entry in the iops, latency, or bw log for every |
3344 | I/O that completes. When writing to the disk log, that can quickly grow to a | |
3345 | very large size. Setting this option makes fio average the each log entry | |
3346 | over the specified period of time, reducing the resolution of the log. See | |
3347 | :option:`log_max_value` as well. Defaults to 0, logging all entries. | |
6fc82095 | 3348 | Also see `Log File Formats`_. |
06842027 | 3349 | |
f80dba8d | 3350 | .. option:: log_hist_msec=int |
06842027 | 3351 | |
f80dba8d MT |
3352 | Same as :option:`log_avg_msec`, but logs entries for completion latency |
3353 | histograms. Computing latency percentiles from averages of intervals using | |
c60ebc45 | 3354 | :option:`log_avg_msec` is inaccurate. Setting this option makes fio log |
f80dba8d MT |
3355 | histogram entries over the specified period of time, reducing log sizes for |
3356 | high IOPS devices while retaining percentile accuracy. See | |
074f0817 SW |
3357 | :option:`log_hist_coarseness` and :option:`write_hist_log` as well. |
3358 | Defaults to 0, meaning histogram logging is disabled. | |
06842027 | 3359 | |
f80dba8d | 3360 | .. option:: log_hist_coarseness=int |
06842027 | 3361 | |
f80dba8d MT |
3362 | Integer ranging from 0 to 6, defining the coarseness of the resolution of |
3363 | the histogram logs enabled with :option:`log_hist_msec`. For each increment | |
3364 | in coarseness, fio outputs half as many bins. Defaults to 0, for which | |
074f0817 SW |
3365 | histogram logs contain 1216 latency bins. See :option:`write_hist_log` |
3366 | and `Log File Formats`_. | |
8b28bd41 | 3367 | |
f80dba8d | 3368 | .. option:: log_max_value=bool |
66c098b8 | 3369 | |
f80dba8d MT |
3370 | If :option:`log_avg_msec` is set, fio logs the average over that window. If |
3371 | you instead want to log the maximum value, set this option to 1. Defaults to | |
3372 | 0, meaning that averaged values are logged. | |
a696fa2a | 3373 | |
589e88b7 | 3374 | .. option:: log_offset=bool |
a696fa2a | 3375 | |
f80dba8d | 3376 | If this is set, the iolog options will include the byte offset for the I/O |
5a83478f SW |
3377 | entry as well as the other data values. Defaults to 0 meaning that |
3378 | offsets are not present in logs. Also see `Log File Formats`_. | |
71bfa161 | 3379 | |
f80dba8d | 3380 | .. option:: log_compression=int |
7de87099 | 3381 | |
f80dba8d MT |
3382 | If this is set, fio will compress the I/O logs as it goes, to keep the |
3383 | memory footprint lower. When a log reaches the specified size, that chunk is | |
3384 | removed and compressed in the background. Given that I/O logs are fairly | |
3385 | highly compressible, this yields a nice memory savings for longer runs. The | |
3386 | downside is that the compression will consume some background CPU cycles, so | |
3387 | it may impact the run. This, however, is also true if the logging ends up | |
3388 | consuming most of the system memory. So pick your poison. The I/O logs are | |
3389 | saved normally at the end of a run, by decompressing the chunks and storing | |
3390 | them in the specified log file. This feature depends on the availability of | |
3391 | zlib. | |
e0b0d892 | 3392 | |
f80dba8d | 3393 | .. option:: log_compression_cpus=str |
e0b0d892 | 3394 | |
f80dba8d MT |
3395 | Define the set of CPUs that are allowed to handle online log compression for |
3396 | the I/O jobs. This can provide better isolation between performance | |
0cf90a62 SW |
3397 | sensitive jobs, and background compression work. See |
3398 | :option:`cpus_allowed` for the format used. | |
9e684a49 | 3399 | |
f80dba8d | 3400 | .. option:: log_store_compressed=bool |
9e684a49 | 3401 | |
f80dba8d MT |
3402 | If set, fio will store the log files in a compressed format. They can be |
3403 | decompressed with fio, using the :option:`--inflate-log` command line | |
3404 | parameter. The files will be stored with a :file:`.fz` suffix. | |
9e684a49 | 3405 | |
f80dba8d | 3406 | .. option:: log_unix_epoch=bool |
9e684a49 | 3407 | |
f80dba8d MT |
3408 | If set, fio will log Unix timestamps to the log files produced by enabling |
3409 | write_type_log for each log type, instead of the default zero-based | |
3410 | timestamps. | |
3411 | ||
3412 | .. option:: block_error_percentiles=bool | |
3413 | ||
3414 | If set, record errors in trim block-sized units from writes and trims and | |
3415 | output a histogram of how many trims it took to get to errors, and what kind | |
3416 | of error was encountered. | |
3417 | ||
3418 | .. option:: bwavgtime=int | |
3419 | ||
3420 | Average the calculated bandwidth over the given time. Value is specified in | |
3421 | milliseconds. If the job also does bandwidth logging through | |
3422 | :option:`write_bw_log`, then the minimum of this option and | |
3423 | :option:`log_avg_msec` will be used. Default: 500ms. | |
3424 | ||
3425 | .. option:: iopsavgtime=int | |
3426 | ||
3427 | Average the calculated IOPS over the given time. Value is specified in | |
3428 | milliseconds. If the job also does IOPS logging through | |
3429 | :option:`write_iops_log`, then the minimum of this option and | |
3430 | :option:`log_avg_msec` will be used. Default: 500ms. | |
3431 | ||
3432 | .. option:: disk_util=bool | |
3433 | ||
3434 | Generate disk utilization statistics, if the platform supports it. | |
3435 | Default: true. | |
3436 | ||
3437 | .. option:: disable_lat=bool | |
3438 | ||
3439 | Disable measurements of total latency numbers. Useful only for cutting back | |
3440 | the number of calls to :manpage:`gettimeofday(2)`, as that does impact | |
3441 | performance at really high IOPS rates. Note that to really get rid of a | |
3442 | large amount of these calls, this option must be used with | |
f75ede1d | 3443 | :option:`disable_slat` and :option:`disable_bw_measurement` as well. |
f80dba8d MT |
3444 | |
3445 | .. option:: disable_clat=bool | |
3446 | ||
3447 | Disable measurements of completion latency numbers. See | |
3448 | :option:`disable_lat`. | |
3449 | ||
3450 | .. option:: disable_slat=bool | |
3451 | ||
3452 | Disable measurements of submission latency numbers. See | |
f50fbdda | 3453 | :option:`disable_lat`. |
f80dba8d | 3454 | |
f75ede1d | 3455 | .. option:: disable_bw_measurement=bool, disable_bw=bool |
f80dba8d MT |
3456 | |
3457 | Disable measurements of throughput/bandwidth numbers. See | |
3458 | :option:`disable_lat`. | |
3459 | ||
dd39b9ce VF |
3460 | .. option:: slat_percentiles=bool |
3461 | ||
3462 | Report submission latency percentiles. Submission latency is not recorded | |
3463 | for synchronous ioengines. | |
3464 | ||
f80dba8d MT |
3465 | .. option:: clat_percentiles=bool |
3466 | ||
dd39b9ce | 3467 | Report completion latency percentiles. |
b599759b JA |
3468 | |
3469 | .. option:: lat_percentiles=bool | |
3470 | ||
dd39b9ce VF |
3471 | Report total latency percentiles. Total latency is the sum of submission |
3472 | latency and completion latency. | |
f80dba8d MT |
3473 | |
3474 | .. option:: percentile_list=float_list | |
3475 | ||
dd39b9ce VF |
3476 | Overwrite the default list of percentiles for latencies and the block error |
3477 | histogram. Each number is a floating point number in the range (0,100], and | |
3478 | the maximum length of the list is 20. Use ``:`` to separate the numbers. For | |
c32ba107 | 3479 | example, ``--percentile_list=99.5:99.9`` will cause fio to report the |
dd39b9ce VF |
3480 | latency durations below which 99.5% and 99.9% of the observed latencies fell, |
3481 | respectively. | |
f80dba8d | 3482 | |
e883cb35 JF |
3483 | .. option:: significant_figures=int |
3484 | ||
c32ba107 JA |
3485 | If using :option:`--output-format` of `normal`, set the significant |
3486 | figures to this value. Higher values will yield more precise IOPS and | |
3487 | throughput units, while lower values will round. Requires a minimum | |
3488 | value of 1 and a maximum value of 10. Defaults to 4. | |
e883cb35 | 3489 | |
f80dba8d MT |
3490 | |
3491 | Error handling | |
3492 | ~~~~~~~~~~~~~~ | |
3493 | ||
3494 | .. option:: exitall_on_error | |
3495 | ||
3496 | When one job finishes in error, terminate the rest. The default is to wait | |
3497 | for each job to finish. | |
3498 | ||
3499 | .. option:: continue_on_error=str | |
3500 | ||
3501 | Normally fio will exit the job on the first observed failure. If this option | |
3502 | is set, fio will continue the job when there is a 'non-fatal error' (EIO or | |
3503 | EILSEQ) until the runtime is exceeded or the I/O size specified is | |
3504 | completed. If this option is used, there are two more stats that are | |
3505 | appended, the total error count and the first error. The error field given | |
3506 | in the stats is the first error that was hit during the run. | |
3507 | ||
3508 | The allowed values are: | |
3509 | ||
3510 | **none** | |
3511 | Exit on any I/O or verify errors. | |
3512 | ||
3513 | **read** | |
3514 | Continue on read errors, exit on all others. | |
3515 | ||
3516 | **write** | |
3517 | Continue on write errors, exit on all others. | |
3518 | ||
3519 | **io** | |
3520 | Continue on any I/O error, exit on all others. | |
3521 | ||
3522 | **verify** | |
3523 | Continue on verify errors, exit on all others. | |
3524 | ||
3525 | **all** | |
3526 | Continue on all errors. | |
3527 | ||
3528 | **0** | |
3529 | Backward-compatible alias for 'none'. | |
3530 | ||
3531 | **1** | |
3532 | Backward-compatible alias for 'all'. | |
3533 | ||
3534 | .. option:: ignore_error=str | |
3535 | ||
3536 | Sometimes you want to ignore some errors during test in that case you can | |
a35ef7cb TK |
3537 | specify error list for each error type, instead of only being able to |
3538 | ignore the default 'non-fatal error' using :option:`continue_on_error`. | |
f80dba8d MT |
3539 | ``ignore_error=READ_ERR_LIST,WRITE_ERR_LIST,VERIFY_ERR_LIST`` errors for |
3540 | given error type is separated with ':'. Error may be symbol ('ENOSPC', | |
3541 | 'ENOMEM') or integer. Example:: | |
3542 | ||
3543 | ignore_error=EAGAIN,ENOSPC:122 | |
3544 | ||
3545 | This option will ignore EAGAIN from READ, and ENOSPC and 122(EDQUOT) from | |
a35ef7cb TK |
3546 | WRITE. This option works by overriding :option:`continue_on_error` with |
3547 | the list of errors for each error type if any. | |
f80dba8d MT |
3548 | |
3549 | .. option:: error_dump=bool | |
3550 | ||
3551 | If set dump every error even if it is non fatal, true by default. If | |
3552 | disabled only fatal error will be dumped. | |
3553 | ||
f75ede1d SW |
3554 | Running predefined workloads |
3555 | ---------------------------- | |
3556 | ||
3557 | Fio includes predefined profiles that mimic the I/O workloads generated by | |
3558 | other tools. | |
3559 | ||
3560 | .. option:: profile=str | |
3561 | ||
3562 | The predefined workload to run. Current profiles are: | |
3563 | ||
3564 | **tiobench** | |
3565 | Threaded I/O bench (tiotest/tiobench) like workload. | |
3566 | ||
3567 | **act** | |
3568 | Aerospike Certification Tool (ACT) like workload. | |
3569 | ||
3570 | To view a profile's additional options use :option:`--cmdhelp` after specifying | |
3571 | the profile. For example:: | |
3572 | ||
f50fbdda | 3573 | $ fio --profile=act --cmdhelp |
f75ede1d SW |
3574 | |
3575 | Act profile options | |
3576 | ~~~~~~~~~~~~~~~~~~~ | |
3577 | ||
3578 | .. option:: device-names=str | |
3579 | :noindex: | |
3580 | ||
3581 | Devices to use. | |
3582 | ||
3583 | .. option:: load=int | |
3584 | :noindex: | |
3585 | ||
3586 | ACT load multiplier. Default: 1. | |
3587 | ||
3588 | .. option:: test-duration=time | |
3589 | :noindex: | |
3590 | ||
947e0fe0 SW |
3591 | How long the entire test takes to run. When the unit is omitted, the value |
3592 | is given in seconds. Default: 24h. | |
f75ede1d SW |
3593 | |
3594 | .. option:: threads-per-queue=int | |
3595 | :noindex: | |
3596 | ||
f50fbdda | 3597 | Number of read I/O threads per device. Default: 8. |
f75ede1d SW |
3598 | |
3599 | .. option:: read-req-num-512-blocks=int | |
3600 | :noindex: | |
3601 | ||
3602 | Number of 512B blocks to read at the time. Default: 3. | |
3603 | ||
3604 | .. option:: large-block-op-kbytes=int | |
3605 | :noindex: | |
3606 | ||
3607 | Size of large block ops in KiB (writes). Default: 131072. | |
3608 | ||
3609 | .. option:: prep | |
3610 | :noindex: | |
3611 | ||
3612 | Set to run ACT prep phase. | |
3613 | ||
3614 | Tiobench profile options | |
3615 | ~~~~~~~~~~~~~~~~~~~~~~~~ | |
3616 | ||
3617 | .. option:: size=str | |
3618 | :noindex: | |
3619 | ||
f50fbdda | 3620 | Size in MiB. |
f75ede1d SW |
3621 | |
3622 | .. option:: block=int | |
3623 | :noindex: | |
3624 | ||
3625 | Block size in bytes. Default: 4096. | |
3626 | ||
3627 | .. option:: numruns=int | |
3628 | :noindex: | |
3629 | ||
3630 | Number of runs. | |
3631 | ||
3632 | .. option:: dir=str | |
3633 | :noindex: | |
3634 | ||
3635 | Test directory. | |
3636 | ||
3637 | .. option:: threads=int | |
3638 | :noindex: | |
3639 | ||
3640 | Number of threads. | |
f80dba8d MT |
3641 | |
3642 | Interpreting the output | |
3643 | ----------------------- | |
3644 | ||
36214730 SW |
3645 | .. |
3646 | Example output was based on the following: | |
3647 | TZ=UTC fio --iodepth=8 --ioengine=null --size=100M --time_based \ | |
3648 | --rate=1256k --bs=14K --name=quick --runtime=1s --name=mixed \ | |
3649 | --runtime=2m --rw=rw | |
3650 | ||
f80dba8d MT |
3651 | Fio spits out a lot of output. While running, fio will display the status of the |
3652 | jobs created. An example of that would be:: | |
3653 | ||
9d25d068 | 3654 | Jobs: 1 (f=1): [_(1),M(1)][24.8%][r=20.5MiB/s,w=23.5MiB/s][r=82,w=94 IOPS][eta 01m:31s] |
f80dba8d | 3655 | |
36214730 SW |
3656 | The characters inside the first set of square brackets denote the current status of |
3657 | each thread. The first character is the first job defined in the job file, and so | |
3658 | forth. The possible values (in typical life cycle order) are: | |
f80dba8d MT |
3659 | |
3660 | +------+-----+-----------------------------------------------------------+ | |
3661 | | Idle | Run | | | |
3662 | +======+=====+===========================================================+ | |
3663 | | P | | Thread setup, but not started. | | |
3664 | +------+-----+-----------------------------------------------------------+ | |
3665 | | C | | Thread created. | | |
3666 | +------+-----+-----------------------------------------------------------+ | |
3667 | | I | | Thread initialized, waiting or generating necessary data. | | |
3668 | +------+-----+-----------------------------------------------------------+ | |
3669 | | | p | Thread running pre-reading file(s). | | |
3670 | +------+-----+-----------------------------------------------------------+ | |
36214730 SW |
3671 | | | / | Thread is in ramp period. | |
3672 | +------+-----+-----------------------------------------------------------+ | |
f80dba8d MT |
3673 | | | R | Running, doing sequential reads. | |
3674 | +------+-----+-----------------------------------------------------------+ | |
3675 | | | r | Running, doing random reads. | | |
3676 | +------+-----+-----------------------------------------------------------+ | |
3677 | | | W | Running, doing sequential writes. | | |
3678 | +------+-----+-----------------------------------------------------------+ | |
3679 | | | w | Running, doing random writes. | | |
3680 | +------+-----+-----------------------------------------------------------+ | |
3681 | | | M | Running, doing mixed sequential reads/writes. | | |
3682 | +------+-----+-----------------------------------------------------------+ | |
3683 | | | m | Running, doing mixed random reads/writes. | | |
3684 | +------+-----+-----------------------------------------------------------+ | |
36214730 SW |
3685 | | | D | Running, doing sequential trims. | |
3686 | +------+-----+-----------------------------------------------------------+ | |
3687 | | | d | Running, doing random trims. | | |
3688 | +------+-----+-----------------------------------------------------------+ | |
3689 | | | F | Running, currently waiting for :manpage:`fsync(2)`. | | |
f80dba8d MT |
3690 | +------+-----+-----------------------------------------------------------+ |
3691 | | | V | Running, doing verification of written data. | | |
3692 | +------+-----+-----------------------------------------------------------+ | |
36214730 SW |
3693 | | f | | Thread finishing. | |
3694 | +------+-----+-----------------------------------------------------------+ | |
f80dba8d MT |
3695 | | E | | Thread exited, not reaped by main thread yet. | |
3696 | +------+-----+-----------------------------------------------------------+ | |
36214730 | 3697 | | _ | | Thread reaped. | |
f80dba8d MT |
3698 | +------+-----+-----------------------------------------------------------+ |
3699 | | X | | Thread reaped, exited with an error. | | |
3700 | +------+-----+-----------------------------------------------------------+ | |
3701 | | K | | Thread reaped, exited due to signal. | | |
3702 | +------+-----+-----------------------------------------------------------+ | |
3703 | ||
36214730 SW |
3704 | .. |
3705 | Example output was based on the following: | |
3706 | TZ=UTC fio --iodepth=8 --ioengine=null --size=100M --runtime=58m \ | |
3707 | --time_based --rate=2512k --bs=256K --numjobs=10 \ | |
3708 | --name=readers --rw=read --name=writers --rw=write | |
3709 | ||
f80dba8d | 3710 | Fio will condense the thread string as not to take up more space on the command |
36214730 | 3711 | line than needed. For instance, if you have 10 readers and 10 writers running, |
f80dba8d MT |
3712 | the output would look like this:: |
3713 | ||
9d25d068 | 3714 | Jobs: 20 (f=20): [R(10),W(10)][4.0%][r=20.5MiB/s,w=23.5MiB/s][r=82,w=94 IOPS][eta 57m:36s] |
f80dba8d | 3715 | |
36214730 SW |
3716 | Note that the status string is displayed in order, so it's possible to tell which of |
3717 | the jobs are currently doing what. In the example above this means that jobs 1--10 | |
3718 | are readers and 11--20 are writers. | |
f80dba8d MT |
3719 | |
3720 | The other values are fairly self explanatory -- number of threads currently | |
36214730 SW |
3721 | running and doing I/O, the number of currently open files (f=), the estimated |
3722 | completion percentage, the rate of I/O since last check (read speed listed first, | |
f50fbdda TK |
3723 | then write speed and optionally trim speed) in terms of bandwidth and IOPS, |
3724 | and time to completion for the current running group. It's impossible to estimate | |
3725 | runtime of the following groups (if any). | |
36214730 SW |
3726 | |
3727 | .. | |
3728 | Example output was based on the following: | |
3729 | TZ=UTC fio --iodepth=16 --ioengine=posixaio --filename=/tmp/fiofile \ | |
3730 | --direct=1 --size=100M --time_based --runtime=50s --rate_iops=89 \ | |
3731 | --bs=7K --name=Client1 --rw=write | |
3732 | ||
3733 | When fio is done (or interrupted by :kbd:`Ctrl-C`), it will show the data for | |
3734 | each thread, group of threads, and disks in that order. For each overall thread (or | |
3735 | group) the output looks like:: | |
3736 | ||
3737 | Client1: (groupid=0, jobs=1): err= 0: pid=16109: Sat Jun 24 12:07:54 2017 | |
3738 | write: IOPS=88, BW=623KiB/s (638kB/s)(30.4MiB/50032msec) | |
3739 | slat (nsec): min=500, max=145500, avg=8318.00, stdev=4781.50 | |
3740 | clat (usec): min=170, max=78367, avg=4019.02, stdev=8293.31 | |
3741 | lat (usec): min=174, max=78375, avg=4027.34, stdev=8291.79 | |
3742 | clat percentiles (usec): | |
3743 | | 1.00th=[ 302], 5.00th=[ 326], 10.00th=[ 343], 20.00th=[ 363], | |
3744 | | 30.00th=[ 392], 40.00th=[ 404], 50.00th=[ 416], 60.00th=[ 445], | |
3745 | | 70.00th=[ 816], 80.00th=[ 6718], 90.00th=[12911], 95.00th=[21627], | |
3746 | | 99.00th=[43779], 99.50th=[51643], 99.90th=[68682], 99.95th=[72877], | |
3747 | | 99.99th=[78119] | |
3748 | bw ( KiB/s): min= 532, max= 686, per=0.10%, avg=622.87, stdev=24.82, samples= 100 | |
3749 | iops : min= 76, max= 98, avg=88.98, stdev= 3.54, samples= 100 | |
29092211 VF |
3750 | lat (usec) : 250=0.04%, 500=64.11%, 750=4.81%, 1000=2.79% |
3751 | lat (msec) : 2=4.16%, 4=1.84%, 10=4.90%, 20=11.33%, 50=5.37% | |
3752 | lat (msec) : 100=0.65% | |
36214730 SW |
3753 | cpu : usr=0.27%, sys=0.18%, ctx=12072, majf=0, minf=21 |
3754 | IO depths : 1=85.0%, 2=13.1%, 4=1.8%, 8=0.1%, 16=0.0%, 32=0.0%, >=64=0.0% | |
3755 | submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0% | |
3756 | complete : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0% | |
3757 | issued rwt: total=0,4450,0, short=0,0,0, dropped=0,0,0 | |
3758 | latency : target=0, window=0, percentile=100.00%, depth=8 | |
3759 | ||
3760 | The job name (or first job's name when using :option:`group_reporting`) is printed, | |
3761 | along with the group id, count of jobs being aggregated, last error id seen (which | |
3762 | is 0 when there are no errors), pid/tid of that thread and the time the job/group | |
3763 | completed. Below are the I/O statistics for each data direction performed (showing | |
3764 | writes in the example above). In the order listed, they denote: | |
3765 | ||
3766 | **read/write/trim** | |
3767 | The string before the colon shows the I/O direction the statistics | |
3768 | are for. **IOPS** is the average I/Os performed per second. **BW** | |
3769 | is the average bandwidth rate shown as: value in power of 2 format | |
3770 | (value in power of 10 format). The last two values show: (**total | |
3771 | I/O performed** in power of 2 format / **runtime** of that thread). | |
f80dba8d MT |
3772 | |
3773 | **slat** | |
36214730 SW |
3774 | Submission latency (**min** being the minimum, **max** being the |
3775 | maximum, **avg** being the average, **stdev** being the standard | |
3776 | deviation). This is the time it took to submit the I/O. For | |
3777 | sync I/O this row is not displayed as the slat is really the | |
3778 | completion latency (since queue/complete is one operation there). | |
3779 | This value can be in nanoseconds, microseconds or milliseconds --- | |
3780 | fio will choose the most appropriate base and print that (in the | |
3781 | example above nanoseconds was the best scale). Note: in :option:`--minimal` mode | |
0d237712 | 3782 | latencies are always expressed in microseconds. |
f80dba8d MT |
3783 | |
3784 | **clat** | |
3785 | Completion latency. Same names as slat, this denotes the time from | |
3786 | submission to completion of the I/O pieces. For sync I/O, clat will | |
3787 | usually be equal (or very close) to 0, as the time from submit to | |
3788 | complete is basically just CPU time (I/O has already been done, see slat | |
3789 | explanation). | |
3790 | ||
29092211 VF |
3791 | **lat** |
3792 | Total latency. Same names as slat and clat, this denotes the time from | |
3793 | when fio created the I/O unit to completion of the I/O operation. | |
3794 | ||
f80dba8d | 3795 | **bw** |
36214730 SW |
3796 | Bandwidth statistics based on samples. Same names as the xlat stats, |
3797 | but also includes the number of samples taken (**samples**) and an | |
3798 | approximate percentage of total aggregate bandwidth this thread | |
3799 | received in its group (**per**). This last value is only really | |
3800 | useful if the threads in this group are on the same disk, since they | |
3801 | are then competing for disk access. | |
3802 | ||
3803 | **iops** | |
3804 | IOPS statistics based on samples. Same names as bw. | |
f80dba8d | 3805 | |
29092211 VF |
3806 | **lat (nsec/usec/msec)** |
3807 | The distribution of I/O completion latencies. This is the time from when | |
3808 | I/O leaves fio and when it gets completed. Unlike the separate | |
3809 | read/write/trim sections above, the data here and in the remaining | |
3810 | sections apply to all I/Os for the reporting group. 250=0.04% means that | |
3811 | 0.04% of the I/Os completed in under 250us. 500=64.11% means that 64.11% | |
3812 | of the I/Os required 250 to 499us for completion. | |
3813 | ||
f80dba8d MT |
3814 | **cpu** |
3815 | CPU usage. User and system time, along with the number of context | |
3816 | switches this thread went through, usage of system and user time, and | |
3817 | finally the number of major and minor page faults. The CPU utilization | |
3818 | numbers are averages for the jobs in that reporting group, while the | |
23a8e176 | 3819 | context and fault counters are summed. |
f80dba8d MT |
3820 | |
3821 | **IO depths** | |
a2140525 SW |
3822 | The distribution of I/O depths over the job lifetime. The numbers are |
3823 | divided into powers of 2 and each entry covers depths from that value | |
3824 | up to those that are lower than the next entry -- e.g., 16= covers | |
3825 | depths from 16 to 31. Note that the range covered by a depth | |
3826 | distribution entry can be different to the range covered by the | |
3827 | equivalent submit/complete distribution entry. | |
f80dba8d MT |
3828 | |
3829 | **IO submit** | |
3830 | How many pieces of I/O were submitting in a single submit call. Each | |
c60ebc45 | 3831 | entry denotes that amount and below, until the previous entry -- e.g., |
a2140525 SW |
3832 | 16=100% means that we submitted anywhere between 9 to 16 I/Os per submit |
3833 | call. Note that the range covered by a submit distribution entry can | |
3834 | be different to the range covered by the equivalent depth distribution | |
3835 | entry. | |
f80dba8d MT |
3836 | |
3837 | **IO complete** | |
3838 | Like the above submit number, but for completions instead. | |
3839 | ||
36214730 SW |
3840 | **IO issued rwt** |
3841 | The number of read/write/trim requests issued, and how many of them were | |
3842 | short or dropped. | |
f80dba8d | 3843 | |
29092211 | 3844 | **IO latency** |
ee21ebee | 3845 | These values are for :option:`latency_target` and related options. When |
29092211 VF |
3846 | these options are engaged, this section describes the I/O depth required |
3847 | to meet the specified latency target. | |
71bfa161 | 3848 | |
36214730 SW |
3849 | .. |
3850 | Example output was based on the following: | |
3851 | TZ=UTC fio --ioengine=null --iodepth=2 --size=100M --numjobs=2 \ | |
3852 | --rate_process=poisson --io_limit=32M --name=read --bs=128k \ | |
3853 | --rate=11M --name=write --rw=write --bs=2k --rate=700k | |
3854 | ||
71bfa161 | 3855 | After each client has been listed, the group statistics are printed. They |
f80dba8d | 3856 | will look like this:: |
71bfa161 | 3857 | |
f80dba8d | 3858 | Run status group 0 (all jobs): |
36214730 SW |
3859 | READ: bw=20.9MiB/s (21.9MB/s), 10.4MiB/s-10.8MiB/s (10.9MB/s-11.3MB/s), io=64.0MiB (67.1MB), run=2973-3069msec |
3860 | WRITE: bw=1231KiB/s (1261kB/s), 616KiB/s-621KiB/s (630kB/s-636kB/s), io=64.0MiB (67.1MB), run=52747-53223msec | |
71bfa161 | 3861 | |
36214730 | 3862 | For each data direction it prints: |
71bfa161 | 3863 | |
36214730 SW |
3864 | **bw** |
3865 | Aggregate bandwidth of threads in this group followed by the | |
3866 | minimum and maximum bandwidth of all the threads in this group. | |
3867 | Values outside of brackets are power-of-2 format and those | |
3868 | within are the equivalent value in a power-of-10 format. | |
f80dba8d | 3869 | **io** |
36214730 SW |
3870 | Aggregate I/O performed of all threads in this group. The |
3871 | format is the same as bw. | |
3872 | **run** | |
3873 | The smallest and longest runtimes of the threads in this group. | |
71bfa161 | 3874 | |
f50fbdda | 3875 | And finally, the disk statistics are printed. This is Linux specific. They will look like this:: |
71bfa161 | 3876 | |
f80dba8d MT |
3877 | Disk stats (read/write): |
3878 | sda: ios=16398/16511, merge=30/162, ticks=6853/819634, in_queue=826487, util=100.00% | |
71bfa161 JA |
3879 | |
3880 | Each value is printed for both reads and writes, with reads first. The | |
3881 | numbers denote: | |
3882 | ||
f80dba8d | 3883 | **ios** |
c60ebc45 | 3884 | Number of I/Os performed by all groups. |
f80dba8d | 3885 | **merge** |
007c7be9 | 3886 | Number of merges performed by the I/O scheduler. |
f80dba8d MT |
3887 | **ticks** |
3888 | Number of ticks we kept the disk busy. | |
36214730 | 3889 | **in_queue** |
f80dba8d MT |
3890 | Total time spent in the disk queue. |
3891 | **util** | |
3892 | The disk utilization. A value of 100% means we kept the disk | |
71bfa161 JA |
3893 | busy constantly, 50% would be a disk idling half of the time. |
3894 | ||
f80dba8d MT |
3895 | It is also possible to get fio to dump the current output while it is running, |
3896 | without terminating the job. To do that, send fio the **USR1** signal. You can | |
3897 | also get regularly timed dumps by using the :option:`--status-interval` | |
3898 | parameter, or by creating a file in :file:`/tmp` named | |
3899 | :file:`fio-dump-status`. If fio sees this file, it will unlink it and dump the | |
3900 | current output status. | |
8423bd11 | 3901 | |
71bfa161 | 3902 | |
f80dba8d MT |
3903 | Terse output |
3904 | ------------ | |
71bfa161 | 3905 | |
f80dba8d MT |
3906 | For scripted usage where you typically want to generate tables or graphs of the |
3907 | results, fio can output the results in a semicolon separated format. The format | |
3908 | is one long line of values, such as:: | |
71bfa161 | 3909 | |
f80dba8d MT |
3910 | 2;card0;0;0;7139336;121836;60004;1;10109;27.932460;116.933948;220;126861;3495.446807;1085.368601;226;126864;3523.635629;1089.012448;24063;99944;50.275485%;59818.274627;5540.657370;7155060;122104;60004;1;8338;29.086342;117.839068;388;128077;5032.488518;1234.785715;391;128085;5061.839412;1236.909129;23436;100928;50.287926%;59964.832030;5644.844189;14.595833%;19.394167%;123706;0;7313;0.1%;0.1%;0.1%;0.1%;0.1%;0.1%;100.0%;0.00%;0.00%;0.00%;0.00%;0.00%;0.00%;0.01%;0.02%;0.05%;0.16%;6.04%;40.40%;52.68%;0.64%;0.01%;0.00%;0.01%;0.00%;0.00%;0.00%;0.00%;0.00% |
3911 | A description of this job goes here. | |
562c2d2f | 3912 | |
4e757af1 VF |
3913 | The job description (if provided) follows on a second line for terse v2. |
3914 | It appears on the same line for other terse versions. | |
71bfa161 | 3915 | |
a7f77fa6 SW |
3916 | To enable terse output, use the :option:`--minimal` or |
3917 | :option:`--output-format`\=terse command line options. The | |
f80dba8d MT |
3918 | first value is the version of the terse output format. If the output has to be |
3919 | changed for some reason, this number will be incremented by 1 to signify that | |
3920 | change. | |
6820cb3b | 3921 | |
a2c95580 | 3922 | Split up, the format is as follows (comments in brackets denote when a |
007c7be9 | 3923 | field was introduced or whether it's specific to some terse version): |
71bfa161 | 3924 | |
f80dba8d MT |
3925 | :: |
3926 | ||
f50fbdda | 3927 | terse version, fio version [v3], jobname, groupid, error |
f80dba8d MT |
3928 | |
3929 | READ status:: | |
3930 | ||
3931 | Total IO (KiB), bandwidth (KiB/sec), IOPS, runtime (msec) | |
3932 | Submission latency: min, max, mean, stdev (usec) | |
3933 | Completion latency: min, max, mean, stdev (usec) | |
3934 | Completion latency percentiles: 20 fields (see below) | |
3935 | Total latency: min, max, mean, stdev (usec) | |
f50fbdda TK |
3936 | Bw (KiB/s): min, max, aggregate percentage of total, mean, stdev, number of samples [v5] |
3937 | IOPS [v5]: min, max, mean, stdev, number of samples | |
f80dba8d MT |
3938 | |
3939 | WRITE status: | |
3940 | ||
3941 | :: | |
3942 | ||
3943 | Total IO (KiB), bandwidth (KiB/sec), IOPS, runtime (msec) | |
3944 | Submission latency: min, max, mean, stdev (usec) | |
247823cc | 3945 | Completion latency: min, max, mean, stdev (usec) |
f80dba8d MT |
3946 | Completion latency percentiles: 20 fields (see below) |
3947 | Total latency: min, max, mean, stdev (usec) | |
f50fbdda TK |
3948 | Bw (KiB/s): min, max, aggregate percentage of total, mean, stdev, number of samples [v5] |
3949 | IOPS [v5]: min, max, mean, stdev, number of samples | |
a2c95580 AH |
3950 | |
3951 | TRIM status [all but version 3]: | |
3952 | ||
f50fbdda | 3953 | Fields are similar to READ/WRITE status. |
f80dba8d MT |
3954 | |
3955 | CPU usage:: | |
3956 | ||
3957 | user, system, context switches, major faults, minor faults | |
3958 | ||
3959 | I/O depths:: | |
3960 | ||
3961 | <=1, 2, 4, 8, 16, 32, >=64 | |
3962 | ||
3963 | I/O latencies microseconds:: | |
3964 | ||
3965 | <=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000 | |
3966 | ||
3967 | I/O latencies milliseconds:: | |
3968 | ||
3969 | <=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000, 2000, >=2000 | |
3970 | ||
a2c95580 | 3971 | Disk utilization [v3]:: |
f80dba8d | 3972 | |
f50fbdda TK |
3973 | disk name, read ios, write ios, read merges, write merges, read ticks, write ticks, |
3974 | time spent in queue, disk utilization percentage | |
f80dba8d MT |
3975 | |
3976 | Additional Info (dependent on continue_on_error, default off):: | |
3977 | ||
3978 | total # errors, first error code | |
3979 | ||
3980 | Additional Info (dependent on description being set):: | |
3981 | ||
3982 | Text description | |
3983 | ||
3984 | Completion latency percentiles can be a grouping of up to 20 sets, so for the | |
3985 | terse output fio writes all of them. Each field will look like this:: | |
1db92cb6 | 3986 | |
f50fbdda | 3987 | 1.00%=6112 |
1db92cb6 | 3988 | |
f80dba8d | 3989 | which is the Xth percentile, and the `usec` latency associated with it. |
1db92cb6 | 3990 | |
f50fbdda | 3991 | For `Disk utilization`, all disks used by fio are shown. So for each disk there |
f80dba8d | 3992 | will be a disk utilization section. |
f2f788dd | 3993 | |
2fc26c3d | 3994 | Below is a single line containing short names for each of the fields in the |
2831be97 | 3995 | minimal output v3, separated by semicolons:: |
2fc26c3d | 3996 | |
f95689d3 | 3997 | terse_version_3;fio_version;jobname;groupid;error;read_kb;read_bandwidth_kb;read_iops;read_runtime_ms;read_slat_min_us;read_slat_max_us;read_slat_mean_us;read_slat_dev_us;read_clat_min_us;read_clat_max_us;read_clat_mean_us;read_clat_dev_us;read_clat_pct01;read_clat_pct02;read_clat_pct03;read_clat_pct04;read_clat_pct05;read_clat_pct06;read_clat_pct07;read_clat_pct08;read_clat_pct09;read_clat_pct10;read_clat_pct11;read_clat_pct12;read_clat_pct13;read_clat_pct14;read_clat_pct15;read_clat_pct16;read_clat_pct17;read_clat_pct18;read_clat_pct19;read_clat_pct20;read_tlat_min_us;read_lat_max_us;read_lat_mean_us;read_lat_dev_us;read_bw_min_kb;read_bw_max_kb;read_bw_agg_pct;read_bw_mean_kb;read_bw_dev_kb;write_kb;write_bandwidth_kb;write_iops;write_runtime_ms;write_slat_min_us;write_slat_max_us;write_slat_mean_us;write_slat_dev_us;write_clat_min_us;write_clat_max_us;write_clat_mean_us;write_clat_dev_us;write_clat_pct01;write_clat_pct02;write_clat_pct03;write_clat_pct04;write_clat_pct05;write_clat_pct06;write_clat_pct07;write_clat_pct08;write_clat_pct09;write_clat_pct10;write_clat_pct11;write_clat_pct12;write_clat_pct13;write_clat_pct14;write_clat_pct15;write_clat_pct16;write_clat_pct17;write_clat_pct18;write_clat_pct19;write_clat_pct20;write_tlat_min_us;write_lat_max_us;write_lat_mean_us;write_lat_dev_us;write_bw_min_kb;write_bw_max_kb;write_bw_agg_pct;write_bw_mean_kb;write_bw_dev_kb;cpu_user;cpu_sys;cpu_csw;cpu_mjf;cpu_minf;iodepth_1;iodepth_2;iodepth_4;iodepth_8;iodepth_16;iodepth_32;iodepth_64;lat_2us;lat_4us;lat_10us;lat_20us;lat_50us;lat_100us;lat_250us;lat_500us;lat_750us;lat_1000us;lat_2ms;lat_4ms;lat_10ms;lat_20ms;lat_50ms;lat_100ms;lat_250ms;lat_500ms;lat_750ms;lat_1000ms;lat_2000ms;lat_over_2000ms;disk_name;disk_read_iops;disk_write_iops;disk_read_merges;disk_write_merges;disk_read_ticks;write_ticks;disk_queue_time;disk_util |
2fc26c3d | 3998 | |
4e757af1 VF |
3999 | In client/server mode terse output differs from what appears when jobs are run |
4000 | locally. Disk utilization data is omitted from the standard terse output and | |
4001 | for v3 and later appears on its own separate line at the end of each terse | |
4002 | reporting cycle. | |
4003 | ||
25c8b9d7 | 4004 | |
44c82dba VF |
4005 | JSON output |
4006 | ------------ | |
4007 | ||
4008 | The `json` output format is intended to be both human readable and convenient | |
4009 | for automated parsing. For the most part its sections mirror those of the | |
4010 | `normal` output. The `runtime` value is reported in msec and the `bw` value is | |
4011 | reported in 1024 bytes per second units. | |
4012 | ||
4013 | ||
d29c4a91 VF |
4014 | JSON+ output |
4015 | ------------ | |
4016 | ||
4017 | The `json+` output format is identical to the `json` output format except that it | |
4018 | adds a full dump of the completion latency bins. Each `bins` object contains a | |
4019 | set of (key, value) pairs where keys are latency durations and values count how | |
4020 | many I/Os had completion latencies of the corresponding duration. For example, | |
4021 | consider: | |
4022 | ||
4023 | "bins" : { "87552" : 1, "89600" : 1, "94720" : 1, "96768" : 1, "97792" : 1, "99840" : 1, "100864" : 2, "103936" : 6, "104960" : 534, "105984" : 5995, "107008" : 7529, ... } | |
4024 | ||
4025 | This data indicates that one I/O required 87,552ns to complete, two I/Os required | |
4026 | 100,864ns to complete, and 7529 I/Os required 107,008ns to complete. | |
4027 | ||
4028 | Also included with fio is a Python script `fio_jsonplus_clat2csv` that takes | |
4029 | json+ output and generates CSV-formatted latency data suitable for plotting. | |
4030 | ||
4031 | The latency durations actually represent the midpoints of latency intervals. | |
f50fbdda | 4032 | For details refer to :file:`stat.h`. |
d29c4a91 VF |
4033 | |
4034 | ||
f80dba8d MT |
4035 | Trace file format |
4036 | ----------------- | |
4037 | ||
4038 | There are two trace file format that you can encounter. The older (v1) format is | |
4039 | unsupported since version 1.20-rc3 (March 2008). It will still be described | |
25c8b9d7 PD |
4040 | below in case that you get an old trace and want to understand it. |
4041 | ||
4042 | In any case the trace is a simple text file with a single action per line. | |
4043 | ||
4044 | ||
f80dba8d MT |
4045 | Trace file format v1 |
4046 | ~~~~~~~~~~~~~~~~~~~~ | |
4047 | ||
4048 | Each line represents a single I/O action in the following format:: | |
4049 | ||
4050 | rw, offset, length | |
25c8b9d7 | 4051 | |
f50fbdda | 4052 | where `rw=0/1` for read/write, and the `offset` and `length` entries being in bytes. |
25c8b9d7 | 4053 | |
22413915 | 4054 | This format is not supported in fio versions >= 1.20-rc3. |
25c8b9d7 | 4055 | |
25c8b9d7 | 4056 | |
f80dba8d MT |
4057 | Trace file format v2 |
4058 | ~~~~~~~~~~~~~~~~~~~~ | |
25c8b9d7 | 4059 | |
f80dba8d MT |
4060 | The second version of the trace file format was added in fio version 1.17. It |
4061 | allows to access more then one file per trace and has a bigger set of possible | |
4062 | file actions. | |
25c8b9d7 | 4063 | |
f80dba8d | 4064 | The first line of the trace file has to be:: |
25c8b9d7 | 4065 | |
f80dba8d | 4066 | fio version 2 iolog |
25c8b9d7 PD |
4067 | |
4068 | Following this can be lines in two different formats, which are described below. | |
4069 | ||
f80dba8d | 4070 | The file management format:: |
25c8b9d7 | 4071 | |
f80dba8d | 4072 | filename action |
25c8b9d7 | 4073 | |
f50fbdda | 4074 | The `filename` is given as an absolute path. The `action` can be one of these: |
25c8b9d7 | 4075 | |
f80dba8d | 4076 | **add** |
f50fbdda | 4077 | Add the given `filename` to the trace. |
f80dba8d | 4078 | **open** |
f50fbdda | 4079 | Open the file with the given `filename`. The `filename` has to have |
f80dba8d MT |
4080 | been added with the **add** action before. |
4081 | **close** | |
f50fbdda | 4082 | Close the file with the given `filename`. The file has to have been |
f80dba8d MT |
4083 | opened before. |
4084 | ||
4085 | ||
4086 | The file I/O action format:: | |
4087 | ||
4088 | filename action offset length | |
4089 | ||
4090 | The `filename` is given as an absolute path, and has to have been added and | |
4091 | opened before it can be used with this format. The `offset` and `length` are | |
4092 | given in bytes. The `action` can be one of these: | |
4093 | ||
4094 | **wait** | |
4095 | Wait for `offset` microseconds. Everything below 100 is discarded. | |
4096 | The time is relative to the previous `wait` statement. | |
4097 | **read** | |
4098 | Read `length` bytes beginning from `offset`. | |
4099 | **write** | |
4100 | Write `length` bytes beginning from `offset`. | |
4101 | **sync** | |
4102 | :manpage:`fsync(2)` the file. | |
4103 | **datasync** | |
4104 | :manpage:`fdatasync(2)` the file. | |
4105 | **trim** | |
4106 | Trim the given file from the given `offset` for `length` bytes. | |
4107 | ||
b9921d1a DZ |
4108 | |
4109 | I/O Replay - Merging Traces | |
4110 | --------------------------- | |
4111 | ||
4112 | Colocation is a common practice used to get the most out of a machine. | |
4113 | Knowing which workloads play nicely with each other and which ones don't is | |
4114 | a much harder task. While fio can replay workloads concurrently via multiple | |
4115 | jobs, it leaves some variability up to the scheduler making results harder to | |
4116 | reproduce. Merging is a way to make the order of events consistent. | |
4117 | ||
4118 | Merging is integrated into I/O replay and done when a | |
4119 | :option:`merge_blktrace_file` is specified. The list of files passed to | |
4120 | :option:`read_iolog` go through the merge process and output a single file | |
4121 | stored to the specified file. The output file is passed on as if it were the | |
4122 | only file passed to :option:`read_iolog`. An example would look like:: | |
4123 | ||
4124 | $ fio --read_iolog="<file1>:<file2>" --merge_blktrace_file="<output_file>" | |
4125 | ||
4126 | Creating only the merged file can be done by passing the command line argument | |
d443e3af | 4127 | :option:`--merge-blktrace-only`. |
b9921d1a | 4128 | |
87a48ada DZ |
4129 | Scaling traces can be done to see the relative impact of any particular trace |
4130 | being slowed down or sped up. :option:`merge_blktrace_scalars` takes in a colon | |
4131 | separated list of percentage scalars. It is index paired with the files passed | |
4132 | to :option:`read_iolog`. | |
4133 | ||
55bfd8c8 DZ |
4134 | With scaling, it may be desirable to match the running time of all traces. |
4135 | This can be done with :option:`merge_blktrace_iters`. It is index paired with | |
4136 | :option:`read_iolog` just like :option:`merge_blktrace_scalars`. | |
4137 | ||
4138 | In an example, given two traces, A and B, each 60s long. If we want to see | |
4139 | the impact of trace A issuing IOs twice as fast and repeat trace A over the | |
4140 | runtime of trace B, the following can be done:: | |
4141 | ||
4142 | $ fio --read_iolog="<trace_a>:"<trace_b>" --merge_blktrace_file"<output_file>" --merge_blktrace_scalars="50:100" --merge_blktrace_iters="2:1" | |
4143 | ||
4144 | This runs trace A at 2x the speed twice for approximately the same runtime as | |
4145 | a single run of trace B. | |
4146 | ||
b9921d1a | 4147 | |
f80dba8d MT |
4148 | CPU idleness profiling |
4149 | ---------------------- | |
4150 | ||
4151 | In some cases, we want to understand CPU overhead in a test. For example, we | |
4152 | test patches for the specific goodness of whether they reduce CPU usage. | |
4153 | Fio implements a balloon approach to create a thread per CPU that runs at idle | |
4154 | priority, meaning that it only runs when nobody else needs the cpu. | |
4155 | By measuring the amount of work completed by the thread, idleness of each CPU | |
4156 | can be derived accordingly. | |
4157 | ||
4158 | An unit work is defined as touching a full page of unsigned characters. Mean and | |
4159 | standard deviation of time to complete an unit work is reported in "unit work" | |
4160 | section. Options can be chosen to report detailed percpu idleness or overall | |
4161 | system idleness by aggregating percpu stats. | |
4162 | ||
4163 | ||
4164 | Verification and triggers | |
4165 | ------------------------- | |
4166 | ||
4167 | Fio is usually run in one of two ways, when data verification is done. The first | |
4168 | is a normal write job of some sort with verify enabled. When the write phase has | |
4169 | completed, fio switches to reads and verifies everything it wrote. The second | |
4170 | model is running just the write phase, and then later on running the same job | |
4171 | (but with reads instead of writes) to repeat the same I/O patterns and verify | |
4172 | the contents. Both of these methods depend on the write phase being completed, | |
4173 | as fio otherwise has no idea how much data was written. | |
4174 | ||
4175 | With verification triggers, fio supports dumping the current write state to | |
4176 | local files. Then a subsequent read verify workload can load this state and know | |
4177 | exactly where to stop. This is useful for testing cases where power is cut to a | |
4178 | server in a managed fashion, for instance. | |
99b9a85a JA |
4179 | |
4180 | A verification trigger consists of two things: | |
4181 | ||
f80dba8d MT |
4182 | 1) Storing the write state of each job. |
4183 | 2) Executing a trigger command. | |
99b9a85a | 4184 | |
f80dba8d MT |
4185 | The write state is relatively small, on the order of hundreds of bytes to single |
4186 | kilobytes. It contains information on the number of completions done, the last X | |
4187 | completions, etc. | |
99b9a85a | 4188 | |
f80dba8d MT |
4189 | A trigger is invoked either through creation ('touch') of a specified file in |
4190 | the system, or through a timeout setting. If fio is run with | |
9207a0cb | 4191 | :option:`--trigger-file`\= :file:`/tmp/trigger-file`, then it will continually |
f80dba8d MT |
4192 | check for the existence of :file:`/tmp/trigger-file`. When it sees this file, it |
4193 | will fire off the trigger (thus saving state, and executing the trigger | |
99b9a85a JA |
4194 | command). |
4195 | ||
f80dba8d MT |
4196 | For client/server runs, there's both a local and remote trigger. If fio is |
4197 | running as a server backend, it will send the job states back to the client for | |
4198 | safe storage, then execute the remote trigger, if specified. If a local trigger | |
4199 | is specified, the server will still send back the write state, but the client | |
4200 | will then execute the trigger. | |
99b9a85a | 4201 | |
f80dba8d MT |
4202 | Verification trigger example |
4203 | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
99b9a85a | 4204 | |
f50fbdda TK |
4205 | Let's say we want to run a powercut test on the remote Linux machine 'server'. |
4206 | Our write workload is in :file:`write-test.fio`. We want to cut power to 'server' at | |
f80dba8d MT |
4207 | some point during the run, and we'll run this test from the safety or our local |
4208 | machine, 'localbox'. On the server, we'll start the fio backend normally:: | |
99b9a85a | 4209 | |
f80dba8d | 4210 | server# fio --server |
99b9a85a | 4211 | |
f80dba8d | 4212 | and on the client, we'll fire off the workload:: |
99b9a85a | 4213 | |
f80dba8d | 4214 | localbox$ fio --client=server --trigger-file=/tmp/my-trigger --trigger-remote="bash -c \"echo b > /proc/sysrq-triger\"" |
99b9a85a | 4215 | |
f80dba8d | 4216 | We set :file:`/tmp/my-trigger` as the trigger file, and we tell fio to execute:: |
99b9a85a | 4217 | |
f80dba8d | 4218 | echo b > /proc/sysrq-trigger |
99b9a85a | 4219 | |
f80dba8d MT |
4220 | on the server once it has received the trigger and sent us the write state. This |
4221 | will work, but it's not **really** cutting power to the server, it's merely | |
4222 | abruptly rebooting it. If we have a remote way of cutting power to the server | |
4223 | through IPMI or similar, we could do that through a local trigger command | |
4502cb42 | 4224 | instead. Let's assume we have a script that does IPMI reboot of a given hostname, |
f80dba8d MT |
4225 | ipmi-reboot. On localbox, we could then have run fio with a local trigger |
4226 | instead:: | |
99b9a85a | 4227 | |
f80dba8d | 4228 | localbox$ fio --client=server --trigger-file=/tmp/my-trigger --trigger="ipmi-reboot server" |
99b9a85a | 4229 | |
f80dba8d MT |
4230 | For this case, fio would wait for the server to send us the write state, then |
4231 | execute ``ipmi-reboot server`` when that happened. | |
4232 | ||
4233 | Loading verify state | |
4234 | ~~~~~~~~~~~~~~~~~~~~ | |
4235 | ||
4502cb42 | 4236 | To load stored write state, a read verification job file must contain the |
f80dba8d | 4237 | :option:`verify_state_load` option. If that is set, fio will load the previously |
99b9a85a | 4238 | stored state. For a local fio run this is done by loading the files directly, |
f80dba8d MT |
4239 | and on a client/server run, the server backend will ask the client to send the |
4240 | files over and load them from there. | |
a3ae5b05 JA |
4241 | |
4242 | ||
f80dba8d MT |
4243 | Log File Formats |
4244 | ---------------- | |
a3ae5b05 JA |
4245 | |
4246 | Fio supports a variety of log file formats, for logging latencies, bandwidth, | |
4247 | and IOPS. The logs share a common format, which looks like this: | |
4248 | ||
5a83478f | 4249 | *time* (`msec`), *value*, *data direction*, *block size* (`bytes`), |
1a953d97 | 4250 | *offset* (`bytes`), *command priority* |
a3ae5b05 | 4251 | |
5a83478f | 4252 | *Time* for the log entry is always in milliseconds. The *value* logged depends |
a3ae5b05 JA |
4253 | on the type of log, it will be one of the following: |
4254 | ||
f80dba8d | 4255 | **Latency log** |
168bb587 | 4256 | Value is latency in nsecs |
f80dba8d MT |
4257 | **Bandwidth log** |
4258 | Value is in KiB/sec | |
4259 | **IOPS log** | |
4260 | Value is IOPS | |
4261 | ||
4262 | *Data direction* is one of the following: | |
4263 | ||
4264 | **0** | |
4265 | I/O is a READ | |
4266 | **1** | |
4267 | I/O is a WRITE | |
4268 | **2** | |
4269 | I/O is a TRIM | |
4270 | ||
15417073 SW |
4271 | The entry's *block size* is always in bytes. The *offset* is the position in bytes |
4272 | from the start of the file for that particular I/O. The logging of the offset can be | |
5a83478f | 4273 | toggled with :option:`log_offset`. |
f80dba8d | 4274 | |
1a953d97 PC |
4275 | *Command priority* is 0 for normal priority and 1 for high priority. This is controlled |
4276 | by the ioengine specific :option:`cmdprio_percentage`. | |
4277 | ||
15417073 SW |
4278 | Fio defaults to logging every individual I/O but when windowed logging is set |
4279 | through :option:`log_avg_msec`, either the average (by default) or the maximum | |
4280 | (:option:`log_max_value` is set) *value* seen over the specified period of time | |
4281 | is recorded. Each *data direction* seen within the window period will aggregate | |
4282 | its values in a separate row. Further, when using windowed logging the *block | |
4283 | size* and *offset* entries will always contain 0. | |
f80dba8d | 4284 | |
4e757af1 | 4285 | |
b8f7e412 | 4286 | Client/Server |
f80dba8d MT |
4287 | ------------- |
4288 | ||
4289 | Normally fio is invoked as a stand-alone application on the machine where the | |
6cf30ac0 SW |
4290 | I/O workload should be generated. However, the backend and frontend of fio can |
4291 | be run separately i.e., the fio server can generate an I/O workload on the "Device | |
4292 | Under Test" while being controlled by a client on another machine. | |
f80dba8d MT |
4293 | |
4294 | Start the server on the machine which has access to the storage DUT:: | |
4295 | ||
f50fbdda | 4296 | $ fio --server=args |
f80dba8d | 4297 | |
dbb257bb | 4298 | where `args` defines what fio listens to. The arguments are of the form |
f80dba8d MT |
4299 | ``type,hostname`` or ``IP,port``. *type* is either ``ip`` (or ip4) for TCP/IP |
4300 | v4, ``ip6`` for TCP/IP v6, or ``sock`` for a local unix domain socket. | |
4301 | *hostname* is either a hostname or IP address, and *port* is the port to listen | |
4302 | to (only valid for TCP/IP, not a local socket). Some examples: | |
4303 | ||
4304 | 1) ``fio --server`` | |
4305 | ||
4306 | Start a fio server, listening on all interfaces on the default port (8765). | |
4307 | ||
4308 | 2) ``fio --server=ip:hostname,4444`` | |
4309 | ||
4310 | Start a fio server, listening on IP belonging to hostname and on port 4444. | |
4311 | ||
4312 | 3) ``fio --server=ip6:::1,4444`` | |
4313 | ||
4314 | Start a fio server, listening on IPv6 localhost ::1 and on port 4444. | |
4315 | ||
4316 | 4) ``fio --server=,4444`` | |
4317 | ||
4318 | Start a fio server, listening on all interfaces on port 4444. | |
4319 | ||
4320 | 5) ``fio --server=1.2.3.4`` | |
4321 | ||
4322 | Start a fio server, listening on IP 1.2.3.4 on the default port. | |
4323 | ||
4324 | 6) ``fio --server=sock:/tmp/fio.sock`` | |
4325 | ||
dbb257bb | 4326 | Start a fio server, listening on the local socket :file:`/tmp/fio.sock`. |
f80dba8d MT |
4327 | |
4328 | Once a server is running, a "client" can connect to the fio server with:: | |
4329 | ||
4330 | fio <local-args> --client=<server> <remote-args> <job file(s)> | |
4331 | ||
4332 | where `local-args` are arguments for the client where it is running, `server` | |
4333 | is the connect string, and `remote-args` and `job file(s)` are sent to the | |
4334 | server. The `server` string follows the same format as it does on the server | |
4335 | side, to allow IP/hostname/socket and port strings. | |
4336 | ||
4337 | Fio can connect to multiple servers this way:: | |
4338 | ||
4339 | fio --client=<server1> <job file(s)> --client=<server2> <job file(s)> | |
4340 | ||
4341 | If the job file is located on the fio server, then you can tell the server to | |
4342 | load a local file as well. This is done by using :option:`--remote-config` :: | |
4343 | ||
4344 | fio --client=server --remote-config /path/to/file.fio | |
4345 | ||
4346 | Then fio will open this local (to the server) job file instead of being passed | |
4347 | one from the client. | |
4348 | ||
4349 | If you have many servers (example: 100 VMs/containers), you can input a pathname | |
4350 | of a file containing host IPs/names as the parameter value for the | |
4351 | :option:`--client` option. For example, here is an example :file:`host.list` | |
4352 | file containing 2 hostnames:: | |
4353 | ||
4354 | host1.your.dns.domain | |
4355 | host2.your.dns.domain | |
4356 | ||
4357 | The fio command would then be:: | |
a3ae5b05 | 4358 | |
f80dba8d | 4359 | fio --client=host.list <job file(s)> |
a3ae5b05 | 4360 | |
f80dba8d MT |
4361 | In this mode, you cannot input server-specific parameters or job files -- all |
4362 | servers receive the same job file. | |
a3ae5b05 | 4363 | |
f80dba8d MT |
4364 | In order to let ``fio --client`` runs use a shared filesystem from multiple |
4365 | hosts, ``fio --client`` now prepends the IP address of the server to the | |
4502cb42 | 4366 | filename. For example, if fio is using the directory :file:`/mnt/nfs/fio` and is |
f80dba8d MT |
4367 | writing filename :file:`fileio.tmp`, with a :option:`--client` `hostfile` |
4368 | containing two hostnames ``h1`` and ``h2`` with IP addresses 192.168.10.120 and | |
4369 | 192.168.10.121, then fio will create two files:: | |
a3ae5b05 | 4370 | |
f80dba8d MT |
4371 | /mnt/nfs/fio/192.168.10.120.fileio.tmp |
4372 | /mnt/nfs/fio/192.168.10.121.fileio.tmp | |
4e757af1 VF |
4373 | |
4374 | Terse output in client/server mode will differ slightly from what is produced | |
4375 | when fio is run in stand-alone mode. See the terse output section for details. |