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d60e92d1 AC |
1 | .TH fio 1 "September 2007" "User Manual" |
2 | .SH NAME | |
3 | fio \- flexible I/O tester | |
4 | .SH SYNOPSIS | |
5 | .B fio | |
6 | [\fIoptions\fR] [\fIjobfile\fR]... | |
7 | .SH DESCRIPTION | |
8 | .B fio | |
9 | is a tool that will spawn a number of threads or processes doing a | |
10 | particular type of I/O action as specified by the user. | |
11 | The typical use of fio is to write a job file matching the I/O load | |
12 | one wants to simulate. | |
13 | .SH OPTIONS | |
14 | .TP | |
49da1240 JA |
15 | .BI \-\-debug \fR=\fPtype |
16 | Enable verbose tracing of various fio actions. May be `all' for all types | |
17 | or individual types separated by a comma (eg \-\-debug=io,file). `help' will | |
18 | list all available tracing options. | |
19 | .TP | |
d60e92d1 AC |
20 | .BI \-\-output \fR=\fPfilename |
21 | Write output to \fIfilename\fR. | |
22 | .TP | |
23 | .BI \-\-timeout \fR=\fPtimeout | |
24 | Limit run time to \fItimeout\fR seconds. | |
25 | .TP | |
26 | .B \-\-latency\-log | |
27 | Generate per-job latency logs. | |
28 | .TP | |
29 | .B \-\-bandwidth\-log | |
30 | Generate per-job bandwidth logs. | |
31 | .TP | |
32 | .B \-\-minimal | |
d1429b5c | 33 | Print statistics in a terse, semicolon-delimited format. |
d60e92d1 | 34 | .TP |
49da1240 JA |
35 | .B \-\-version |
36 | Display version information and exit. | |
37 | .TP | |
38 | .B \-\-terse\-version \fR=\fPversion | |
39 | Set terse version output format. | |
40 | .TP | |
41 | .B \-\-help | |
42 | Display usage information and exit. | |
43 | .TP | |
44 | .BI \-\-cmdhelp \fR=\fPcommand | |
45 | Print help information for \fIcommand\fR. May be `all' for all commands. | |
46 | .TP | |
d60e92d1 AC |
47 | .BI \-\-showcmd \fR=\fPjobfile |
48 | Convert \fIjobfile\fR to a set of command-line options. | |
49 | .TP | |
50 | .B \-\-readonly | |
51 | Enable read-only safety checks. | |
52 | .TP | |
53 | .BI \-\-eta \fR=\fPwhen | |
54 | Specifies when real-time ETA estimate should be printed. \fIwhen\fR may | |
55 | be one of `always', `never' or `auto'. | |
56 | .TP | |
49da1240 JA |
57 | .BI \-\-readonly |
58 | Turn on safety read-only checks, preventing any attempted write. | |
59 | .TP | |
c0a5d35e | 60 | .BI \-\-section \fR=\fPsec |
49da1240 | 61 | Only run section \fIsec\fR from job file. Multiple of these options can be given, adding more sections to run. |
c0a5d35e | 62 | .TP |
49da1240 JA |
63 | .BI \-\-alloc\-size \fR=\fPkb |
64 | Set the internal smalloc pool size to \fIkb\fP kilobytes. | |
d60e92d1 | 65 | .TP |
49da1240 JA |
66 | .BI \-\-warnings\-fatal |
67 | All fio parser warnings are fatal, causing fio to exit with an error. | |
9183788d | 68 | .TP |
49da1240 JA |
69 | .BI \-\-max\-jobs \fR=\fPnr |
70 | Set the maximum allowed number of jobs (threads/processes) to suport. | |
d60e92d1 | 71 | .TP |
49da1240 JA |
72 | .BI \-\-server \fR=\fPargs |
73 | Start a backend server, with \fIargs\fP specifying what to listen to. See client/server section. | |
f57a9c59 | 74 | .TP |
49da1240 JA |
75 | .BI \-\-daemonize \fR=\fPpidfile |
76 | Background a fio server, writing the pid to the given pid file. | |
77 | .TP | |
78 | .BI \-\-client \fR=\fPhost | |
79 | Instead of running the jobs locally, send and run them on the given host. | |
d60e92d1 AC |
80 | .SH "JOB FILE FORMAT" |
81 | Job files are in `ini' format. They consist of one or more | |
82 | job definitions, which begin with a job name in square brackets and | |
83 | extend to the next job name. The job name can be any ASCII string | |
84 | except `global', which has a special meaning. Following the job name is | |
85 | a sequence of zero or more parameters, one per line, that define the | |
86 | behavior of the job. Any line starting with a `;' or `#' character is | |
d1429b5c | 87 | considered a comment and ignored. |
d9956b64 AC |
88 | .P |
89 | If \fIjobfile\fR is specified as `-', the job file will be read from | |
90 | standard input. | |
d60e92d1 AC |
91 | .SS "Global Section" |
92 | The global section contains default parameters for jobs specified in the | |
93 | job file. A job is only affected by global sections residing above it, | |
94 | and there may be any number of global sections. Specific job definitions | |
95 | may override any parameter set in global sections. | |
96 | .SH "JOB PARAMETERS" | |
97 | .SS Types | |
98 | Some parameters may take arguments of a specific type. The types used are: | |
99 | .TP | |
100 | .I str | |
101 | String: a sequence of alphanumeric characters. | |
102 | .TP | |
103 | .I int | |
d60e92d1 | 104 | SI integer: a whole number, possibly containing a suffix denoting the base unit |
b09da8fa JA |
105 | of the value. Accepted suffixes are `k', 'M', 'G', 'T', and 'P', denoting |
106 | kilo (1024), mega (1024^2), giga (1024^3), tera (1024^4), and peta (1024^5) | |
107 | respectively. The suffix is not case sensitive. If prefixed with '0x', the | |
5982a925 MS |
108 | value is assumed to be base 16 (hexadecimal). A suffix may include a trailing 'b', |
109 | for instance 'kb' is identical to 'k'. You can specify a base 10 value | |
57fc29fa JA |
110 | by using 'KiB', 'MiB', 'GiB', etc. This is useful for disk drives where |
111 | values are often given in base 10 values. Specifying '30GiB' will get you | |
112 | 30*1000^3 bytes. | |
d60e92d1 AC |
113 | .TP |
114 | .I bool | |
115 | Boolean: a true or false value. `0' denotes false, `1' denotes true. | |
116 | .TP | |
117 | .I irange | |
118 | Integer range: a range of integers specified in the format | |
d1429b5c AC |
119 | \fIlower\fR:\fIupper\fR or \fIlower\fR\-\fIupper\fR. \fIlower\fR and |
120 | \fIupper\fR may contain a suffix as described above. If an option allows two | |
121 | sets of ranges, they are separated with a `,' or `/' character. For example: | |
122 | `8\-8k/8M\-4G'. | |
83349190 YH |
123 | .TP |
124 | .I float_list | |
125 | List of floating numbers: A list of floating numbers, separated by | |
126 | a ':' charcater. | |
d60e92d1 AC |
127 | .SS "Parameter List" |
128 | .TP | |
129 | .BI name \fR=\fPstr | |
d9956b64 | 130 | May be used to override the job name. On the command line, this parameter |
d60e92d1 AC |
131 | has the special purpose of signalling the start of a new job. |
132 | .TP | |
133 | .BI description \fR=\fPstr | |
134 | Human-readable description of the job. It is printed when the job is run, but | |
135 | otherwise has no special purpose. | |
136 | .TP | |
137 | .BI directory \fR=\fPstr | |
138 | Prefix filenames with this directory. Used to place files in a location other | |
139 | than `./'. | |
140 | .TP | |
141 | .BI filename \fR=\fPstr | |
142 | .B fio | |
143 | normally makes up a file name based on the job name, thread number, and file | |
d1429b5c AC |
144 | number. If you want to share files between threads in a job or several jobs, |
145 | specify a \fIfilename\fR for each of them to override the default. If the I/O | |
146 | engine used is `net', \fIfilename\fR is the host and port to connect to in the | |
147 | format \fIhost\fR/\fIport\fR. If the I/O engine is file-based, you can specify | |
148 | a number of files by separating the names with a `:' character. `\-' is a | |
149 | reserved name, meaning stdin or stdout, depending on the read/write direction | |
150 | set. | |
d60e92d1 | 151 | .TP |
3ce9dcaf JA |
152 | .BI lockfile \fR=\fPstr |
153 | Fio defaults to not locking any files before it does IO to them. If a file or | |
154 | file descriptor is shared, fio can serialize IO to that file to make the end | |
155 | result consistent. This is usual for emulating real workloads that share files. | |
156 | The lock modes are: | |
157 | .RS | |
158 | .RS | |
159 | .TP | |
160 | .B none | |
161 | No locking. This is the default. | |
162 | .TP | |
163 | .B exclusive | |
164 | Only one thread or process may do IO at the time, excluding all others. | |
165 | .TP | |
166 | .B readwrite | |
167 | Read-write locking on the file. Many readers may access the file at the same | |
168 | time, but writes get exclusive access. | |
169 | .RE | |
170 | .P | |
171 | The option may be post-fixed with a lock batch number. If set, then each | |
172 | thread/process may do that amount of IOs to the file before giving up the lock. | |
173 | Since lock acquisition is expensive, batching the lock/unlocks will speed up IO. | |
174 | .RE | |
175 | .P | |
d60e92d1 AC |
176 | .BI opendir \fR=\fPstr |
177 | Recursively open any files below directory \fIstr\fR. | |
178 | .TP | |
179 | .BI readwrite \fR=\fPstr "\fR,\fP rw" \fR=\fPstr | |
180 | Type of I/O pattern. Accepted values are: | |
181 | .RS | |
182 | .RS | |
183 | .TP | |
184 | .B read | |
d1429b5c | 185 | Sequential reads. |
d60e92d1 AC |
186 | .TP |
187 | .B write | |
d1429b5c | 188 | Sequential writes. |
d60e92d1 AC |
189 | .TP |
190 | .B randread | |
d1429b5c | 191 | Random reads. |
d60e92d1 AC |
192 | .TP |
193 | .B randwrite | |
d1429b5c | 194 | Random writes. |
d60e92d1 AC |
195 | .TP |
196 | .B rw | |
d1429b5c | 197 | Mixed sequential reads and writes. |
d60e92d1 AC |
198 | .TP |
199 | .B randrw | |
d1429b5c | 200 | Mixed random reads and writes. |
d60e92d1 AC |
201 | .RE |
202 | .P | |
38dad62d JA |
203 | For mixed I/O, the default split is 50/50. For certain types of io the result |
204 | may still be skewed a bit, since the speed may be different. It is possible to | |
205 | specify a number of IO's to do before getting a new offset, this is one by | |
206 | appending a `:\fI<nr>\fR to the end of the string given. For a random read, it | |
207 | would look like \fBrw=randread:8\fR for passing in an offset modifier with a | |
059b0802 JA |
208 | value of 8. If the postfix is used with a sequential IO pattern, then the value |
209 | specified will be added to the generated offset for each IO. For instance, | |
210 | using \fBrw=write:4k\fR will skip 4k for every write. It turns sequential IO | |
211 | into sequential IO with holes. See the \fBrw_sequencer\fR option. | |
d60e92d1 AC |
212 | .RE |
213 | .TP | |
38dad62d JA |
214 | .BI rw_sequencer \fR=\fPstr |
215 | If an offset modifier is given by appending a number to the \fBrw=<str>\fR line, | |
216 | then this option controls how that number modifies the IO offset being | |
217 | generated. Accepted values are: | |
218 | .RS | |
219 | .RS | |
220 | .TP | |
221 | .B sequential | |
222 | Generate sequential offset | |
223 | .TP | |
224 | .B identical | |
225 | Generate the same offset | |
226 | .RE | |
227 | .P | |
228 | \fBsequential\fR is only useful for random IO, where fio would normally | |
229 | generate a new random offset for every IO. If you append eg 8 to randread, you | |
230 | would get a new random offset for every 8 IO's. The result would be a seek for | |
231 | only every 8 IO's, instead of for every IO. Use \fBrw=randread:8\fR to specify | |
232 | that. As sequential IO is already sequential, setting \fBsequential\fR for that | |
233 | would not result in any differences. \fBidentical\fR behaves in a similar | |
234 | fashion, except it sends the same offset 8 number of times before generating a | |
235 | new offset. | |
236 | .RE | |
237 | .P | |
238 | .TP | |
90fef2d1 JA |
239 | .BI kb_base \fR=\fPint |
240 | The base unit for a kilobyte. The defacto base is 2^10, 1024. Storage | |
241 | manufacturers like to use 10^3 or 1000 as a base ten unit instead, for obvious | |
242 | reasons. Allow values are 1024 or 1000, with 1024 being the default. | |
243 | .TP | |
d60e92d1 AC |
244 | .BI randrepeat \fR=\fPbool |
245 | Seed the random number generator in a predictable way so results are repeatable | |
d1429b5c | 246 | across runs. Default: true. |
d60e92d1 | 247 | .TP |
2615cc4b JA |
248 | .BI use_os_rand \fR=\fPbool |
249 | Fio can either use the random generator supplied by the OS to generator random | |
250 | offsets, or it can use it's own internal generator (based on Tausworthe). | |
251 | Default is to use the internal generator, which is often of better quality and | |
252 | faster. Default: false. | |
253 | .TP | |
a596f047 EG |
254 | .BI fallocate \fR=\fPstr |
255 | Whether pre-allocation is performed when laying down files. Accepted values | |
256 | are: | |
257 | .RS | |
258 | .RS | |
259 | .TP | |
260 | .B none | |
261 | Do not pre-allocate space. | |
262 | .TP | |
263 | .B posix | |
264 | Pre-allocate via posix_fallocate(). | |
265 | .TP | |
266 | .B keep | |
267 | Pre-allocate via fallocate() with FALLOC_FL_KEEP_SIZE set. | |
268 | .TP | |
269 | .B 0 | |
270 | Backward-compatible alias for 'none'. | |
271 | .TP | |
272 | .B 1 | |
273 | Backward-compatible alias for 'posix'. | |
274 | .RE | |
275 | .P | |
276 | May not be available on all supported platforms. 'keep' is only | |
277 | available on Linux. If using ZFS on Solaris this must be set to 'none' | |
278 | because ZFS doesn't support it. Default: 'posix'. | |
279 | .RE | |
7bc8c2cf | 280 | .TP |
d60e92d1 | 281 | .BI fadvise_hint \fR=\fPbool |
d1429b5c AC |
282 | Disable use of \fIposix_fadvise\fR\|(2) to advise the kernel what I/O patterns |
283 | are likely to be issued. Default: true. | |
d60e92d1 | 284 | .TP |
f7fa2653 | 285 | .BI size \fR=\fPint |
d60e92d1 AC |
286 | Total size of I/O for this job. \fBfio\fR will run until this many bytes have |
287 | been transfered, unless limited by other options (\fBruntime\fR, for instance). | |
d7c8be03 | 288 | Unless \fBnrfiles\fR and \fBfilesize\fR options are given, this amount will be |
d6667268 JA |
289 | divided between the available files for the job. If not set, fio will use the |
290 | full size of the given files or devices. If the the files do not exist, size | |
7bb59102 JA |
291 | must be given. It is also possible to give size as a percentage between 1 and |
292 | 100. If size=20% is given, fio will use 20% of the full size of the given files | |
293 | or devices. | |
d60e92d1 | 294 | .TP |
74586c1e | 295 | .BI fill_device \fR=\fPbool "\fR,\fB fill_fs" \fR=\fPbool |
3ce9dcaf JA |
296 | Sets size to something really large and waits for ENOSPC (no space left on |
297 | device) as the terminating condition. Only makes sense with sequential write. | |
298 | For a read workload, the mount point will be filled first then IO started on | |
4f12432e JA |
299 | the result. This option doesn't make sense if operating on a raw device node, |
300 | since the size of that is already known by the file system. Additionally, | |
301 | writing beyond end-of-device will not return ENOSPC there. | |
3ce9dcaf | 302 | .TP |
d60e92d1 AC |
303 | .BI filesize \fR=\fPirange |
304 | Individual file sizes. May be a range, in which case \fBfio\fR will select sizes | |
d1429b5c AC |
305 | for files at random within the given range, limited to \fBsize\fR in total (if |
306 | that is given). If \fBfilesize\fR is not specified, each created file is the | |
307 | same size. | |
d60e92d1 | 308 | .TP |
f7fa2653 | 309 | .BI blocksize \fR=\fPint[,int] "\fR,\fB bs" \fR=\fPint[,int] |
d60e92d1 | 310 | Block size for I/O units. Default: 4k. Values for reads and writes can be |
656ebab7 | 311 | specified separately in the format \fIread\fR,\fIwrite\fR, either of |
d60e92d1 AC |
312 | which may be empty to leave that value at its default. |
313 | .TP | |
9183788d | 314 | .BI blocksize_range \fR=\fPirange[,irange] "\fR,\fB bsrange" \fR=\fPirange[,irange] |
d1429b5c AC |
315 | Specify a range of I/O block sizes. The issued I/O unit will always be a |
316 | multiple of the minimum size, unless \fBblocksize_unaligned\fR is set. Applies | |
9183788d | 317 | to both reads and writes if only one range is given, but can be specified |
656ebab7 | 318 | separately with a comma seperating the values. Example: bsrange=1k-4k,2k-8k. |
9183788d JA |
319 | Also (see \fBblocksize\fR). |
320 | .TP | |
321 | .BI bssplit \fR=\fPstr | |
322 | This option allows even finer grained control of the block sizes issued, | |
323 | not just even splits between them. With this option, you can weight various | |
324 | block sizes for exact control of the issued IO for a job that has mixed | |
325 | block sizes. The format of the option is bssplit=blocksize/percentage, | |
5982a925 | 326 | optionally adding as many definitions as needed separated by a colon. |
9183788d | 327 | Example: bssplit=4k/10:64k/50:32k/40 would issue 50% 64k blocks, 10% 4k |
c83cdd3e JA |
328 | blocks and 40% 32k blocks. \fBbssplit\fR also supports giving separate |
329 | splits to reads and writes. The format is identical to what the | |
330 | \fBbs\fR option accepts, the read and write parts are separated with a | |
331 | comma. | |
d60e92d1 AC |
332 | .TP |
333 | .B blocksize_unaligned\fR,\fP bs_unaligned | |
d1429b5c AC |
334 | If set, any size in \fBblocksize_range\fR may be used. This typically won't |
335 | work with direct I/O, as that normally requires sector alignment. | |
d60e92d1 | 336 | .TP |
2b7a01d0 | 337 | .BI blockalign \fR=\fPint[,int] "\fR,\fB ba" \fR=\fPint[,int] |
639ce0f3 MS |
338 | At what boundary to align random IO offsets. Defaults to the same as 'blocksize' |
339 | the minimum blocksize given. Minimum alignment is typically 512b | |
2b7a01d0 JA |
340 | for using direct IO, though it usually depends on the hardware block size. |
341 | This option is mutually exclusive with using a random map for files, so it | |
342 | will turn off that option. | |
43602667 | 343 | .TP |
d60e92d1 AC |
344 | .B zero_buffers |
345 | Initialise buffers with all zeros. Default: fill buffers with random data. | |
346 | .TP | |
901bb994 JA |
347 | .B refill_buffers |
348 | If this option is given, fio will refill the IO buffers on every submit. The | |
349 | default is to only fill it at init time and reuse that data. Only makes sense | |
350 | if zero_buffers isn't specified, naturally. If data verification is enabled, | |
351 | refill_buffers is also automatically enabled. | |
352 | .TP | |
fd68418e JA |
353 | .BI scramble_buffers \fR=\fPbool |
354 | If \fBrefill_buffers\fR is too costly and the target is using data | |
355 | deduplication, then setting this option will slightly modify the IO buffer | |
356 | contents to defeat normal de-dupe attempts. This is not enough to defeat | |
357 | more clever block compression attempts, but it will stop naive dedupe | |
358 | of blocks. Default: true. | |
359 | .TP | |
d60e92d1 AC |
360 | .BI nrfiles \fR=\fPint |
361 | Number of files to use for this job. Default: 1. | |
362 | .TP | |
363 | .BI openfiles \fR=\fPint | |
364 | Number of files to keep open at the same time. Default: \fBnrfiles\fR. | |
365 | .TP | |
366 | .BI file_service_type \fR=\fPstr | |
367 | Defines how files to service are selected. The following types are defined: | |
368 | .RS | |
369 | .RS | |
370 | .TP | |
371 | .B random | |
372 | Choose a file at random | |
373 | .TP | |
374 | .B roundrobin | |
375 | Round robin over open files (default). | |
6b7f6851 JA |
376 | .B sequential |
377 | Do each file in the set sequentially. | |
d60e92d1 AC |
378 | .RE |
379 | .P | |
380 | The number of I/Os to issue before switching a new file can be specified by | |
381 | appending `:\fIint\fR' to the service type. | |
382 | .RE | |
383 | .TP | |
384 | .BI ioengine \fR=\fPstr | |
385 | Defines how the job issues I/O. The following types are defined: | |
386 | .RS | |
387 | .RS | |
388 | .TP | |
389 | .B sync | |
390 | Basic \fIread\fR\|(2) or \fIwrite\fR\|(2) I/O. \fIfseek\fR\|(2) is used to | |
391 | position the I/O location. | |
392 | .TP | |
a31041ea | 393 | .B psync |
394 | Basic \fIpread\fR\|(2) or \fIpwrite\fR\|(2) I/O. | |
395 | .TP | |
9183788d JA |
396 | .B vsync |
397 | Basic \fIreadv\fR\|(2) or \fIwritev\fR\|(2) I/O. Will emulate queuing by | |
398 | coalescing adjacents IOs into a single submission. | |
399 | .TP | |
d60e92d1 | 400 | .B libaio |
c44b1ff5 JA |
401 | Linux native asynchronous I/O. This engine also has a sub-option, |
402 | \fBuserspace_reap\fR. To set it, use \fBioengine=libaio:userspace_reap\fR. | |
403 | Normally, with the libaio engine in use, fio will use the | |
404 | \fIio_getevents\fR\|(3) system call to reap newly returned events. With this | |
405 | flag turned on, the AIO ring will be read directly from user-space to reap | |
406 | events. The reaping mode is only enabled when polling for a minimum of \fB0\fR | |
407 | events (eg when \fBiodepth_batch_complete=0\fR). | |
d60e92d1 AC |
408 | .TP |
409 | .B posixaio | |
03e20d68 BC |
410 | POSIX asynchronous I/O using \fIaio_read\fR\|(3) and \fIaio_write\fR\|(3). |
411 | .TP | |
412 | .B solarisaio | |
413 | Solaris native asynchronous I/O. | |
414 | .TP | |
415 | .B windowsaio | |
416 | Windows native asynchronous I/O. | |
d60e92d1 AC |
417 | .TP |
418 | .B mmap | |
d1429b5c AC |
419 | File is memory mapped with \fImmap\fR\|(2) and data copied using |
420 | \fImemcpy\fR\|(3). | |
d60e92d1 AC |
421 | .TP |
422 | .B splice | |
d1429b5c AC |
423 | \fIsplice\fR\|(2) is used to transfer the data and \fIvmsplice\fR\|(2) to |
424 | transfer data from user-space to the kernel. | |
d60e92d1 AC |
425 | .TP |
426 | .B syslet-rw | |
427 | Use the syslet system calls to make regular read/write asynchronous. | |
428 | .TP | |
429 | .B sg | |
430 | SCSI generic sg v3 I/O. May be either synchronous using the SG_IO ioctl, or if | |
d1429b5c AC |
431 | the target is an sg character device, we use \fIread\fR\|(2) and |
432 | \fIwrite\fR\|(2) for asynchronous I/O. | |
d60e92d1 AC |
433 | .TP |
434 | .B null | |
435 | Doesn't transfer any data, just pretends to. Mainly used to exercise \fBfio\fR | |
436 | itself and for debugging and testing purposes. | |
437 | .TP | |
438 | .B net | |
439 | Transfer over the network. \fBfilename\fR must be set appropriately to | |
0fd666bf JA |
440 | `\fIhost\fR,\fIport\fR,\fItype\fR' regardless of data direction. \fItype\fR |
441 | is one of \fBtcp\fR, \fBudp\fR, or \fBunix\fR. For UNIX domain sockets, | |
442 | the \fIhost\fR parameter is a file system path. | |
d60e92d1 AC |
443 | .TP |
444 | .B netsplice | |
445 | Like \fBnet\fR, but uses \fIsplice\fR\|(2) and \fIvmsplice\fR\|(2) to map data | |
446 | and send/receive. | |
447 | .TP | |
53aec0a4 | 448 | .B cpuio |
d60e92d1 AC |
449 | Doesn't transfer any data, but burns CPU cycles according to \fBcpuload\fR and |
450 | \fBcpucycles\fR parameters. | |
451 | .TP | |
452 | .B guasi | |
453 | The GUASI I/O engine is the Generic Userspace Asynchronous Syscall Interface | |
454 | approach to asycnronous I/O. | |
d1429b5c AC |
455 | .br |
456 | See <http://www.xmailserver.org/guasi\-lib.html>. | |
d60e92d1 | 457 | .TP |
21b8aee8 | 458 | .B rdma |
85286c5c BVA |
459 | The RDMA I/O engine supports both RDMA memory semantics (RDMA_WRITE/RDMA_READ) |
460 | and channel semantics (Send/Recv) for the InfiniBand, RoCE and iWARP protocols. | |
21b8aee8 | 461 | .TP |
d60e92d1 AC |
462 | .B external |
463 | Loads an external I/O engine object file. Append the engine filename as | |
464 | `:\fIenginepath\fR'. | |
465 | .RE | |
466 | .RE | |
467 | .TP | |
468 | .BI iodepth \fR=\fPint | |
8489dae4 SK |
469 | Number of I/O units to keep in flight against the file. Note that increasing |
470 | iodepth beyond 1 will not affect synchronous ioengines (except for small | |
ee72ca09 JA |
471 | degress when verify_async is in use). Even async engines my impose OS |
472 | restrictions causing the desired depth not to be achieved. This may happen on | |
473 | Linux when using libaio and not setting \fBdirect\fR=1, since buffered IO is | |
474 | not async on that OS. Keep an eye on the IO depth distribution in the | |
475 | fio output to verify that the achieved depth is as expected. Default: 1. | |
d60e92d1 AC |
476 | .TP |
477 | .BI iodepth_batch \fR=\fPint | |
478 | Number of I/Os to submit at once. Default: \fBiodepth\fR. | |
479 | .TP | |
3ce9dcaf JA |
480 | .BI iodepth_batch_complete \fR=\fPint |
481 | This defines how many pieces of IO to retrieve at once. It defaults to 1 which | |
482 | means that we'll ask for a minimum of 1 IO in the retrieval process from the | |
483 | kernel. The IO retrieval will go on until we hit the limit set by | |
484 | \fBiodepth_low\fR. If this variable is set to 0, then fio will always check for | |
485 | completed events before queuing more IO. This helps reduce IO latency, at the | |
486 | cost of more retrieval system calls. | |
487 | .TP | |
d60e92d1 AC |
488 | .BI iodepth_low \fR=\fPint |
489 | Low watermark indicating when to start filling the queue again. Default: | |
490 | \fBiodepth\fR. | |
491 | .TP | |
492 | .BI direct \fR=\fPbool | |
493 | If true, use non-buffered I/O (usually O_DIRECT). Default: false. | |
494 | .TP | |
495 | .BI buffered \fR=\fPbool | |
496 | If true, use buffered I/O. This is the opposite of the \fBdirect\fR parameter. | |
497 | Default: true. | |
498 | .TP | |
f7fa2653 | 499 | .BI offset \fR=\fPint |
d60e92d1 AC |
500 | Offset in the file to start I/O. Data before the offset will not be touched. |
501 | .TP | |
502 | .BI fsync \fR=\fPint | |
d1429b5c AC |
503 | How many I/Os to perform before issuing an \fBfsync\fR\|(2) of dirty data. If |
504 | 0, don't sync. Default: 0. | |
d60e92d1 | 505 | .TP |
5f9099ea JA |
506 | .BI fdatasync \fR=\fPint |
507 | Like \fBfsync\fR, but uses \fBfdatasync\fR\|(2) instead to only sync the | |
508 | data parts of the file. Default: 0. | |
509 | .TP | |
e76b1da4 JA |
510 | .BI sync_file_range \fR=\fPstr:int |
511 | Use sync_file_range() for every \fRval\fP number of write operations. Fio will | |
512 | track range of writes that have happened since the last sync_file_range() call. | |
513 | \fRstr\fP can currently be one or more of: | |
514 | .RS | |
515 | .TP | |
516 | .B wait_before | |
517 | SYNC_FILE_RANGE_WAIT_BEFORE | |
518 | .TP | |
519 | .B write | |
520 | SYNC_FILE_RANGE_WRITE | |
521 | .TP | |
522 | .B wait_after | |
523 | SYNC_FILE_RANGE_WRITE | |
524 | .TP | |
525 | .RE | |
526 | .P | |
527 | So if you do sync_file_range=wait_before,write:8, fio would use | |
528 | \fBSYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE\fP for every 8 writes. | |
529 | Also see the sync_file_range(2) man page. This option is Linux specific. | |
530 | .TP | |
d60e92d1 | 531 | .BI overwrite \fR=\fPbool |
d1429b5c | 532 | If writing, setup the file first and do overwrites. Default: false. |
d60e92d1 AC |
533 | .TP |
534 | .BI end_fsync \fR=\fPbool | |
d1429b5c | 535 | Sync file contents when job exits. Default: false. |
d60e92d1 AC |
536 | .TP |
537 | .BI fsync_on_close \fR=\fPbool | |
538 | If true, sync file contents on close. This differs from \fBend_fsync\fR in that | |
d1429b5c | 539 | it will happen on every close, not just at the end of the job. Default: false. |
d60e92d1 AC |
540 | .TP |
541 | .BI rwmixcycle \fR=\fPint | |
542 | How many milliseconds before switching between reads and writes for a mixed | |
543 | workload. Default: 500ms. | |
544 | .TP | |
545 | .BI rwmixread \fR=\fPint | |
546 | Percentage of a mixed workload that should be reads. Default: 50. | |
547 | .TP | |
548 | .BI rwmixwrite \fR=\fPint | |
d1429b5c | 549 | Percentage of a mixed workload that should be writes. If \fBrwmixread\fR and |
c35dd7a6 JA |
550 | \fBrwmixwrite\fR are given and do not sum to 100%, the latter of the two |
551 | overrides the first. This may interfere with a given rate setting, if fio is | |
552 | asked to limit reads or writes to a certain rate. If that is the case, then | |
553 | the distribution may be skewed. Default: 50. | |
d60e92d1 AC |
554 | .TP |
555 | .B norandommap | |
556 | Normally \fBfio\fR will cover every block of the file when doing random I/O. If | |
557 | this parameter is given, a new offset will be chosen without looking at past | |
558 | I/O history. This parameter is mutually exclusive with \fBverify\fR. | |
559 | .TP | |
744492c9 | 560 | .BI softrandommap \fR=\fPbool |
3ce9dcaf JA |
561 | See \fBnorandommap\fR. If fio runs with the random block map enabled and it |
562 | fails to allocate the map, if this option is set it will continue without a | |
563 | random block map. As coverage will not be as complete as with random maps, this | |
564 | option is disabled by default. | |
565 | .TP | |
d60e92d1 AC |
566 | .BI nice \fR=\fPint |
567 | Run job with given nice value. See \fInice\fR\|(2). | |
568 | .TP | |
569 | .BI prio \fR=\fPint | |
570 | Set I/O priority value of this job between 0 (highest) and 7 (lowest). See | |
571 | \fIionice\fR\|(1). | |
572 | .TP | |
573 | .BI prioclass \fR=\fPint | |
574 | Set I/O priority class. See \fIionice\fR\|(1). | |
575 | .TP | |
576 | .BI thinktime \fR=\fPint | |
577 | Stall job for given number of microseconds between issuing I/Os. | |
578 | .TP | |
579 | .BI thinktime_spin \fR=\fPint | |
580 | Pretend to spend CPU time for given number of microseconds, sleeping the rest | |
581 | of the time specified by \fBthinktime\fR. Only valid if \fBthinktime\fR is set. | |
582 | .TP | |
583 | .BI thinktime_blocks \fR=\fPint | |
584 | Number of blocks to issue before waiting \fBthinktime\fR microseconds. | |
585 | Default: 1. | |
586 | .TP | |
587 | .BI rate \fR=\fPint | |
c35dd7a6 JA |
588 | Cap bandwidth used by this job. The number is in bytes/sec, the normal postfix |
589 | rules apply. You can use \fBrate\fR=500k to limit reads and writes to 500k each, | |
590 | or you can specify read and writes separately. Using \fBrate\fR=1m,500k would | |
591 | limit reads to 1MB/sec and writes to 500KB/sec. Capping only reads or writes | |
592 | can be done with \fBrate\fR=,500k or \fBrate\fR=500k,. The former will only | |
593 | limit writes (to 500KB/sec), the latter will only limit reads. | |
d60e92d1 AC |
594 | .TP |
595 | .BI ratemin \fR=\fPint | |
596 | Tell \fBfio\fR to do whatever it can to maintain at least the given bandwidth. | |
c35dd7a6 JA |
597 | Failing to meet this requirement will cause the job to exit. The same format |
598 | as \fBrate\fR is used for read vs write separation. | |
d60e92d1 AC |
599 | .TP |
600 | .BI rate_iops \fR=\fPint | |
c35dd7a6 JA |
601 | Cap the bandwidth to this number of IOPS. Basically the same as rate, just |
602 | specified independently of bandwidth. The same format as \fBrate\fR is used for | |
603 | read vs write seperation. If \fBblocksize\fR is a range, the smallest block | |
604 | size is used as the metric. | |
d60e92d1 AC |
605 | .TP |
606 | .BI rate_iops_min \fR=\fPint | |
c35dd7a6 JA |
607 | If this rate of I/O is not met, the job will exit. The same format as \fBrate\fR |
608 | is used for read vs write seperation. | |
d60e92d1 AC |
609 | .TP |
610 | .BI ratecycle \fR=\fPint | |
611 | Average bandwidth for \fBrate\fR and \fBratemin\fR over this number of | |
612 | milliseconds. Default: 1000ms. | |
613 | .TP | |
614 | .BI cpumask \fR=\fPint | |
615 | Set CPU affinity for this job. \fIint\fR is a bitmask of allowed CPUs the job | |
616 | may run on. See \fBsched_setaffinity\fR\|(2). | |
617 | .TP | |
618 | .BI cpus_allowed \fR=\fPstr | |
619 | Same as \fBcpumask\fR, but allows a comma-delimited list of CPU numbers. | |
620 | .TP | |
621 | .BI startdelay \fR=\fPint | |
622 | Delay start of job for the specified number of seconds. | |
623 | .TP | |
624 | .BI runtime \fR=\fPint | |
625 | Terminate processing after the specified number of seconds. | |
626 | .TP | |
627 | .B time_based | |
628 | If given, run for the specified \fBruntime\fR duration even if the files are | |
629 | completely read or written. The same workload will be repeated as many times | |
630 | as \fBruntime\fR allows. | |
631 | .TP | |
901bb994 JA |
632 | .BI ramp_time \fR=\fPint |
633 | If set, fio will run the specified workload for this amount of time before | |
634 | logging any performance numbers. Useful for letting performance settle before | |
635 | logging results, thus minimizing the runtime required for stable results. Note | |
c35dd7a6 JA |
636 | that the \fBramp_time\fR is considered lead in time for a job, thus it will |
637 | increase the total runtime if a special timeout or runtime is specified. | |
901bb994 | 638 | .TP |
d60e92d1 AC |
639 | .BI invalidate \fR=\fPbool |
640 | Invalidate buffer-cache for the file prior to starting I/O. Default: true. | |
641 | .TP | |
642 | .BI sync \fR=\fPbool | |
643 | Use synchronous I/O for buffered writes. For the majority of I/O engines, | |
d1429b5c | 644 | this means using O_SYNC. Default: false. |
d60e92d1 AC |
645 | .TP |
646 | .BI iomem \fR=\fPstr "\fR,\fP mem" \fR=\fPstr | |
647 | Allocation method for I/O unit buffer. Allowed values are: | |
648 | .RS | |
649 | .RS | |
650 | .TP | |
651 | .B malloc | |
652 | Allocate memory with \fImalloc\fR\|(3). | |
653 | .TP | |
654 | .B shm | |
655 | Use shared memory buffers allocated through \fIshmget\fR\|(2). | |
656 | .TP | |
657 | .B shmhuge | |
658 | Same as \fBshm\fR, but use huge pages as backing. | |
659 | .TP | |
660 | .B mmap | |
661 | Use \fImmap\fR\|(2) for allocation. Uses anonymous memory unless a filename | |
662 | is given after the option in the format `:\fIfile\fR'. | |
663 | .TP | |
664 | .B mmaphuge | |
665 | Same as \fBmmap\fR, but use huge files as backing. | |
666 | .RE | |
667 | .P | |
668 | The amount of memory allocated is the maximum allowed \fBblocksize\fR for the | |
669 | job multiplied by \fBiodepth\fR. For \fBshmhuge\fR or \fBmmaphuge\fR to work, | |
670 | the system must have free huge pages allocated. \fBmmaphuge\fR also needs to | |
2e266ba6 JA |
671 | have hugetlbfs mounted, and \fIfile\fR must point there. At least on Linux, |
672 | huge pages must be manually allocated. See \fB/proc/sys/vm/nr_hugehages\fR | |
673 | and the documentation for that. Normally you just need to echo an appropriate | |
674 | number, eg echoing 8 will ensure that the OS has 8 huge pages ready for | |
675 | use. | |
d60e92d1 AC |
676 | .RE |
677 | .TP | |
d392365e | 678 | .BI iomem_align \fR=\fPint "\fR,\fP mem_align" \fR=\fPint |
d529ee19 JA |
679 | This indiciates the memory alignment of the IO memory buffers. Note that the |
680 | given alignment is applied to the first IO unit buffer, if using \fBiodepth\fR | |
681 | the alignment of the following buffers are given by the \fBbs\fR used. In | |
682 | other words, if using a \fBbs\fR that is a multiple of the page sized in the | |
683 | system, all buffers will be aligned to this value. If using a \fBbs\fR that | |
684 | is not page aligned, the alignment of subsequent IO memory buffers is the | |
685 | sum of the \fBiomem_align\fR and \fBbs\fR used. | |
686 | .TP | |
f7fa2653 | 687 | .BI hugepage\-size \fR=\fPint |
d60e92d1 | 688 | Defines the size of a huge page. Must be at least equal to the system setting. |
b22989b9 | 689 | Should be a multiple of 1MB. Default: 4MB. |
d60e92d1 AC |
690 | .TP |
691 | .B exitall | |
692 | Terminate all jobs when one finishes. Default: wait for each job to finish. | |
693 | .TP | |
694 | .BI bwavgtime \fR=\fPint | |
695 | Average bandwidth calculations over the given time in milliseconds. Default: | |
696 | 500ms. | |
697 | .TP | |
c8eeb9df JA |
698 | .BI iopsavgtime \fR=\fPint |
699 | Average IOPS calculations over the given time in milliseconds. Default: | |
700 | 500ms. | |
701 | .TP | |
d60e92d1 | 702 | .BI create_serialize \fR=\fPbool |
d1429b5c | 703 | If true, serialize file creation for the jobs. Default: true. |
d60e92d1 AC |
704 | .TP |
705 | .BI create_fsync \fR=\fPbool | |
706 | \fIfsync\fR\|(2) data file after creation. Default: true. | |
707 | .TP | |
6b7f6851 JA |
708 | .BI create_on_open \fR=\fPbool |
709 | If true, the files are not created until they are opened for IO by the job. | |
710 | .TP | |
e9f48479 JA |
711 | .BI pre_read \fR=\fPbool |
712 | If this is given, files will be pre-read into memory before starting the given | |
713 | IO operation. This will also clear the \fR \fBinvalidate\fR flag, since it is | |
9c0d2241 JA |
714 | pointless to pre-read and then drop the cache. This will only work for IO |
715 | engines that are seekable, since they allow you to read the same data | |
716 | multiple times. Thus it will not work on eg network or splice IO. | |
e9f48479 | 717 | .TP |
d60e92d1 AC |
718 | .BI unlink \fR=\fPbool |
719 | Unlink job files when done. Default: false. | |
720 | .TP | |
721 | .BI loops \fR=\fPint | |
722 | Specifies the number of iterations (runs of the same workload) of this job. | |
723 | Default: 1. | |
724 | .TP | |
725 | .BI do_verify \fR=\fPbool | |
726 | Run the verify phase after a write phase. Only valid if \fBverify\fR is set. | |
727 | Default: true. | |
728 | .TP | |
729 | .BI verify \fR=\fPstr | |
730 | Method of verifying file contents after each iteration of the job. Allowed | |
731 | values are: | |
732 | .RS | |
733 | .RS | |
734 | .TP | |
b892dc08 | 735 | .B md5 crc16 crc32 crc32c crc32c-intel crc64 crc7 sha256 sha512 sha1 |
0539d758 JA |
736 | Store appropriate checksum in the header of each block. crc32c-intel is |
737 | hardware accelerated SSE4.2 driven, falls back to regular crc32c if | |
738 | not supported by the system. | |
d60e92d1 AC |
739 | .TP |
740 | .B meta | |
741 | Write extra information about each I/O (timestamp, block number, etc.). The | |
996093bb | 742 | block number is verified. See \fBverify_pattern\fR as well. |
d60e92d1 AC |
743 | .TP |
744 | .B null | |
745 | Pretend to verify. Used for testing internals. | |
746 | .RE | |
b892dc08 JA |
747 | |
748 | This option can be used for repeated burn-in tests of a system to make sure | |
749 | that the written data is also correctly read back. If the data direction given | |
750 | is a read or random read, fio will assume that it should verify a previously | |
751 | written file. If the data direction includes any form of write, the verify will | |
752 | be of the newly written data. | |
d60e92d1 AC |
753 | .RE |
754 | .TP | |
755 | .BI verify_sort \fR=\fPbool | |
756 | If true, written verify blocks are sorted if \fBfio\fR deems it to be faster to | |
757 | read them back in a sorted manner. Default: true. | |
758 | .TP | |
f7fa2653 | 759 | .BI verify_offset \fR=\fPint |
d60e92d1 | 760 | Swap the verification header with data somewhere else in the block before |
d1429b5c | 761 | writing. It is swapped back before verifying. |
d60e92d1 | 762 | .TP |
f7fa2653 | 763 | .BI verify_interval \fR=\fPint |
d60e92d1 AC |
764 | Write the verification header for this number of bytes, which should divide |
765 | \fBblocksize\fR. Default: \fBblocksize\fR. | |
766 | .TP | |
996093bb JA |
767 | .BI verify_pattern \fR=\fPstr |
768 | If set, fio will fill the io buffers with this pattern. Fio defaults to filling | |
769 | with totally random bytes, but sometimes it's interesting to fill with a known | |
770 | pattern for io verification purposes. Depending on the width of the pattern, | |
771 | fio will fill 1/2/3/4 bytes of the buffer at the time(it can be either a | |
772 | decimal or a hex number). The verify_pattern if larger than a 32-bit quantity | |
773 | has to be a hex number that starts with either "0x" or "0X". Use with | |
774 | \fBverify\fP=meta. | |
775 | .TP | |
d60e92d1 AC |
776 | .BI verify_fatal \fR=\fPbool |
777 | If true, exit the job on the first observed verification failure. Default: | |
778 | false. | |
779 | .TP | |
b463e936 JA |
780 | .BI verify_dump \fR=\fPbool |
781 | If set, dump the contents of both the original data block and the data block we | |
782 | read off disk to files. This allows later analysis to inspect just what kind of | |
783 | data corruption occurred. On by default. | |
784 | .TP | |
e8462bd8 JA |
785 | .BI verify_async \fR=\fPint |
786 | Fio will normally verify IO inline from the submitting thread. This option | |
787 | takes an integer describing how many async offload threads to create for IO | |
788 | verification instead, causing fio to offload the duty of verifying IO contents | |
c85c324c JA |
789 | to one or more separate threads. If using this offload option, even sync IO |
790 | engines can benefit from using an \fBiodepth\fR setting higher than 1, as it | |
791 | allows them to have IO in flight while verifies are running. | |
e8462bd8 JA |
792 | .TP |
793 | .BI verify_async_cpus \fR=\fPstr | |
794 | Tell fio to set the given CPU affinity on the async IO verification threads. | |
795 | See \fBcpus_allowed\fP for the format used. | |
796 | .TP | |
6f87418f JA |
797 | .BI verify_backlog \fR=\fPint |
798 | Fio will normally verify the written contents of a job that utilizes verify | |
799 | once that job has completed. In other words, everything is written then | |
800 | everything is read back and verified. You may want to verify continually | |
801 | instead for a variety of reasons. Fio stores the meta data associated with an | |
802 | IO block in memory, so for large verify workloads, quite a bit of memory would | |
092f707f DN |
803 | be used up holding this meta data. If this option is enabled, fio will write |
804 | only N blocks before verifying these blocks. | |
6f87418f JA |
805 | .TP |
806 | .BI verify_backlog_batch \fR=\fPint | |
807 | Control how many blocks fio will verify if verify_backlog is set. If not set, | |
808 | will default to the value of \fBverify_backlog\fR (meaning the entire queue is | |
092f707f DN |
809 | read back and verified). If \fBverify_backlog_batch\fR is less than |
810 | \fBverify_backlog\fR then not all blocks will be verified, if | |
811 | \fBverify_backlog_batch\fR is larger than \fBverify_backlog\fR, some blocks | |
812 | will be verified more than once. | |
6f87418f | 813 | .TP |
d392365e | 814 | .B stonewall "\fR,\fP wait_for_previous" |
5982a925 | 815 | Wait for preceding jobs in the job file to exit before starting this one. |
d60e92d1 AC |
816 | \fBstonewall\fR implies \fBnew_group\fR. |
817 | .TP | |
818 | .B new_group | |
819 | Start a new reporting group. If not given, all jobs in a file will be part | |
820 | of the same reporting group, unless separated by a stonewall. | |
821 | .TP | |
822 | .BI numjobs \fR=\fPint | |
823 | Number of clones (processes/threads performing the same workload) of this job. | |
824 | Default: 1. | |
825 | .TP | |
826 | .B group_reporting | |
827 | If set, display per-group reports instead of per-job when \fBnumjobs\fR is | |
828 | specified. | |
829 | .TP | |
830 | .B thread | |
831 | Use threads created with \fBpthread_create\fR\|(3) instead of processes created | |
832 | with \fBfork\fR\|(2). | |
833 | .TP | |
f7fa2653 | 834 | .BI zonesize \fR=\fPint |
d60e92d1 AC |
835 | Divide file into zones of the specified size in bytes. See \fBzoneskip\fR. |
836 | .TP | |
f7fa2653 | 837 | .BI zoneskip \fR=\fPint |
d1429b5c | 838 | Skip the specified number of bytes when \fBzonesize\fR bytes of data have been |
d60e92d1 AC |
839 | read. |
840 | .TP | |
841 | .BI write_iolog \fR=\fPstr | |
5b42a488 SH |
842 | Write the issued I/O patterns to the specified file. Specify a separate file |
843 | for each job, otherwise the iologs will be interspersed and the file may be | |
844 | corrupt. | |
d60e92d1 AC |
845 | .TP |
846 | .BI read_iolog \fR=\fPstr | |
847 | Replay the I/O patterns contained in the specified file generated by | |
848 | \fBwrite_iolog\fR, or may be a \fBblktrace\fR binary file. | |
849 | .TP | |
64bbb865 DN |
850 | .BI replay_no_stall \fR=\fPint |
851 | While replaying I/O patterns using \fBread_iolog\fR the default behavior | |
852 | attempts to respect timing information between I/Os. Enabling | |
853 | \fBreplay_no_stall\fR causes I/Os to be replayed as fast as possible while | |
854 | still respecting ordering. | |
855 | .TP | |
d1c46c04 DN |
856 | .BI replay_redirect \fR=\fPstr |
857 | While replaying I/O patterns using \fBread_iolog\fR the default behavior | |
858 | is to replay the IOPS onto the major/minor device that each IOP was recorded | |
859 | from. Setting \fBreplay_redirect\fR causes all IOPS to be replayed onto the | |
860 | single specified device regardless of the device it was recorded from. | |
861 | .TP | |
836bad52 | 862 | .BI write_bw_log \fR=\fPstr |
901bb994 JA |
863 | If given, write a bandwidth log of the jobs in this job file. Can be used to |
864 | store data of the bandwidth of the jobs in their lifetime. The included | |
865 | fio_generate_plots script uses gnuplot to turn these text files into nice | |
866 | graphs. See \fBwrite_log_log\fR for behaviour of given filename. For this | |
867 | option, the postfix is _bw.log. | |
d60e92d1 | 868 | .TP |
836bad52 | 869 | .BI write_lat_log \fR=\fPstr |
901bb994 JA |
870 | Same as \fBwrite_bw_log\fR, but writes I/O completion latencies. If no |
871 | filename is given with this option, the default filename of "jobname_type.log" | |
872 | is used. Even if the filename is given, fio will still append the type of log. | |
873 | .TP | |
c8eeb9df JA |
874 | .BI write_iops_log \fR=\fPstr |
875 | Same as \fBwrite_bw_log\fR, but writes IOPS. If no filename is given with this | |
876 | option, the default filename of "jobname_type.log" is used. Even if the | |
877 | filename is given, fio will still append the type of log. | |
878 | .TP | |
836bad52 | 879 | .BI disable_lat \fR=\fPbool |
02af0988 | 880 | Disable measurements of total latency numbers. Useful only for cutting |
901bb994 JA |
881 | back the number of calls to gettimeofday, as that does impact performance at |
882 | really high IOPS rates. Note that to really get rid of a large amount of these | |
883 | calls, this option must be used with disable_slat and disable_bw as well. | |
884 | .TP | |
836bad52 | 885 | .BI disable_clat \fR=\fPbool |
c95f9daf | 886 | Disable measurements of completion latency numbers. See \fBdisable_lat\fR. |
02af0988 | 887 | .TP |
836bad52 | 888 | .BI disable_slat \fR=\fPbool |
02af0988 | 889 | Disable measurements of submission latency numbers. See \fBdisable_lat\fR. |
901bb994 | 890 | .TP |
836bad52 | 891 | .BI disable_bw_measurement \fR=\fPbool |
02af0988 | 892 | Disable measurements of throughput/bandwidth numbers. See \fBdisable_lat\fR. |
d60e92d1 | 893 | .TP |
f7fa2653 | 894 | .BI lockmem \fR=\fPint |
d60e92d1 AC |
895 | Pin the specified amount of memory with \fBmlock\fR\|(2). Can be used to |
896 | simulate a smaller amount of memory. | |
897 | .TP | |
898 | .BI exec_prerun \fR=\fPstr | |
899 | Before running the job, execute the specified command with \fBsystem\fR\|(3). | |
900 | .TP | |
901 | .BI exec_postrun \fR=\fPstr | |
902 | Same as \fBexec_prerun\fR, but the command is executed after the job completes. | |
903 | .TP | |
904 | .BI ioscheduler \fR=\fPstr | |
905 | Attempt to switch the device hosting the file to the specified I/O scheduler. | |
906 | .TP | |
907 | .BI cpuload \fR=\fPint | |
908 | If the job is a CPU cycle-eater, attempt to use the specified percentage of | |
909 | CPU cycles. | |
910 | .TP | |
911 | .BI cpuchunks \fR=\fPint | |
912 | If the job is a CPU cycle-eater, split the load into cycles of the | |
913 | given time in milliseconds. | |
914 | .TP | |
915 | .BI disk_util \fR=\fPbool | |
d1429b5c | 916 | Generate disk utilization statistics if the platform supports it. Default: true. |
901bb994 JA |
917 | .TP |
918 | .BI gtod_reduce \fR=\fPbool | |
919 | Enable all of the gettimeofday() reducing options (disable_clat, disable_slat, | |
920 | disable_bw) plus reduce precision of the timeout somewhat to really shrink the | |
921 | gettimeofday() call count. With this option enabled, we only do about 0.4% of | |
922 | the gtod() calls we would have done if all time keeping was enabled. | |
923 | .TP | |
924 | .BI gtod_cpu \fR=\fPint | |
925 | Sometimes it's cheaper to dedicate a single thread of execution to just getting | |
926 | the current time. Fio (and databases, for instance) are very intensive on | |
927 | gettimeofday() calls. With this option, you can set one CPU aside for doing | |
928 | nothing but logging current time to a shared memory location. Then the other | |
929 | threads/processes that run IO workloads need only copy that segment, instead of | |
930 | entering the kernel with a gettimeofday() call. The CPU set aside for doing | |
931 | these time calls will be excluded from other uses. Fio will manually clear it | |
932 | from the CPU mask of other jobs. | |
f2bba182 | 933 | .TP |
a696fa2a JA |
934 | .BI cgroup \fR=\fPstr |
935 | Add job to this control group. If it doesn't exist, it will be created. | |
6adb38a1 JA |
936 | The system must have a mounted cgroup blkio mount point for this to work. If |
937 | your system doesn't have it mounted, you can do so with: | |
938 | ||
5982a925 | 939 | # mount \-t cgroup \-o blkio none /cgroup |
a696fa2a JA |
940 | .TP |
941 | .BI cgroup_weight \fR=\fPint | |
942 | Set the weight of the cgroup to this value. See the documentation that comes | |
943 | with the kernel, allowed values are in the range of 100..1000. | |
e0b0d892 | 944 | .TP |
7de87099 VG |
945 | .BI cgroup_nodelete \fR=\fPbool |
946 | Normally fio will delete the cgroups it has created after the job completion. | |
947 | To override this behavior and to leave cgroups around after the job completion, | |
948 | set cgroup_nodelete=1. This can be useful if one wants to inspect various | |
949 | cgroup files after job completion. Default: false | |
950 | .TP | |
e0b0d892 JA |
951 | .BI uid \fR=\fPint |
952 | Instead of running as the invoking user, set the user ID to this value before | |
953 | the thread/process does any work. | |
954 | .TP | |
955 | .BI gid \fR=\fPint | |
956 | Set group ID, see \fBuid\fR. | |
83349190 YH |
957 | .TP |
958 | .BI clat_percentiles \fR=\fPbool | |
959 | Enable the reporting of percentiles of completion latencies. | |
960 | .TP | |
961 | .BI percentile_list \fR=\fPfloat_list | |
962 | Overwrite the default list of percentiles for completion | |
963 | latencies. Each number is a floating number in the range (0,100], and | |
964 | the maximum length of the list is 20. Use ':' to separate the | |
3eb07285 | 965 | numbers. For example, \-\-percentile_list=99.5:99.9 will cause fio to |
83349190 YH |
966 | report the values of completion latency below which 99.5% and 99.9% of |
967 | the observed latencies fell, respectively. | |
d60e92d1 | 968 | .SH OUTPUT |
d1429b5c AC |
969 | While running, \fBfio\fR will display the status of the created jobs. For |
970 | example: | |
d60e92d1 | 971 | .RS |
d1429b5c | 972 | .P |
d60e92d1 AC |
973 | Threads: 1: [_r] [24.8% done] [ 13509/ 8334 kb/s] [eta 00h:01m:31s] |
974 | .RE | |
975 | .P | |
d1429b5c AC |
976 | The characters in the first set of brackets denote the current status of each |
977 | threads. The possible values are: | |
978 | .P | |
979 | .PD 0 | |
d60e92d1 AC |
980 | .RS |
981 | .TP | |
982 | .B P | |
983 | Setup but not started. | |
984 | .TP | |
985 | .B C | |
986 | Thread created. | |
987 | .TP | |
988 | .B I | |
989 | Initialized, waiting. | |
990 | .TP | |
991 | .B R | |
992 | Running, doing sequential reads. | |
993 | .TP | |
994 | .B r | |
995 | Running, doing random reads. | |
996 | .TP | |
997 | .B W | |
998 | Running, doing sequential writes. | |
999 | .TP | |
1000 | .B w | |
1001 | Running, doing random writes. | |
1002 | .TP | |
1003 | .B M | |
1004 | Running, doing mixed sequential reads/writes. | |
1005 | .TP | |
1006 | .B m | |
1007 | Running, doing mixed random reads/writes. | |
1008 | .TP | |
1009 | .B F | |
1010 | Running, currently waiting for \fBfsync\fR\|(2). | |
1011 | .TP | |
1012 | .B V | |
1013 | Running, verifying written data. | |
1014 | .TP | |
1015 | .B E | |
1016 | Exited, not reaped by main thread. | |
1017 | .TP | |
1018 | .B \- | |
1019 | Exited, thread reaped. | |
1020 | .RE | |
d1429b5c | 1021 | .PD |
d60e92d1 AC |
1022 | .P |
1023 | The second set of brackets shows the estimated completion percentage of | |
1024 | the current group. The third set shows the read and write I/O rate, | |
1025 | respectively. Finally, the estimated run time of the job is displayed. | |
1026 | .P | |
1027 | When \fBfio\fR completes (or is interrupted by Ctrl-C), it will show data | |
1028 | for each thread, each group of threads, and each disk, in that order. | |
1029 | .P | |
1030 | Per-thread statistics first show the threads client number, group-id, and | |
1031 | error code. The remaining figures are as follows: | |
1032 | .RS | |
d60e92d1 AC |
1033 | .TP |
1034 | .B io | |
1035 | Number of megabytes of I/O performed. | |
1036 | .TP | |
1037 | .B bw | |
1038 | Average data rate (bandwidth). | |
1039 | .TP | |
1040 | .B runt | |
1041 | Threads run time. | |
1042 | .TP | |
1043 | .B slat | |
1044 | Submission latency minimum, maximum, average and standard deviation. This is | |
1045 | the time it took to submit the I/O. | |
1046 | .TP | |
1047 | .B clat | |
1048 | Completion latency minimum, maximum, average and standard deviation. This | |
1049 | is the time between submission and completion. | |
1050 | .TP | |
1051 | .B bw | |
1052 | Bandwidth minimum, maximum, percentage of aggregate bandwidth received, average | |
1053 | and standard deviation. | |
1054 | .TP | |
1055 | .B cpu | |
1056 | CPU usage statistics. Includes user and system time, number of context switches | |
1057 | this thread went through and number of major and minor page faults. | |
1058 | .TP | |
1059 | .B IO depths | |
1060 | Distribution of I/O depths. Each depth includes everything less than (or equal) | |
1061 | to it, but greater than the previous depth. | |
1062 | .TP | |
1063 | .B IO issued | |
1064 | Number of read/write requests issued, and number of short read/write requests. | |
1065 | .TP | |
1066 | .B IO latencies | |
1067 | Distribution of I/O completion latencies. The numbers follow the same pattern | |
1068 | as \fBIO depths\fR. | |
1069 | .RE | |
d60e92d1 AC |
1070 | .P |
1071 | The group statistics show: | |
d1429b5c | 1072 | .PD 0 |
d60e92d1 AC |
1073 | .RS |
1074 | .TP | |
1075 | .B io | |
1076 | Number of megabytes I/O performed. | |
1077 | .TP | |
1078 | .B aggrb | |
1079 | Aggregate bandwidth of threads in the group. | |
1080 | .TP | |
1081 | .B minb | |
1082 | Minimum average bandwidth a thread saw. | |
1083 | .TP | |
1084 | .B maxb | |
1085 | Maximum average bandwidth a thread saw. | |
1086 | .TP | |
1087 | .B mint | |
d1429b5c | 1088 | Shortest runtime of threads in the group. |
d60e92d1 AC |
1089 | .TP |
1090 | .B maxt | |
1091 | Longest runtime of threads in the group. | |
1092 | .RE | |
d1429b5c | 1093 | .PD |
d60e92d1 AC |
1094 | .P |
1095 | Finally, disk statistics are printed with reads first: | |
d1429b5c | 1096 | .PD 0 |
d60e92d1 AC |
1097 | .RS |
1098 | .TP | |
1099 | .B ios | |
1100 | Number of I/Os performed by all groups. | |
1101 | .TP | |
1102 | .B merge | |
1103 | Number of merges in the I/O scheduler. | |
1104 | .TP | |
1105 | .B ticks | |
1106 | Number of ticks we kept the disk busy. | |
1107 | .TP | |
1108 | .B io_queue | |
1109 | Total time spent in the disk queue. | |
1110 | .TP | |
1111 | .B util | |
1112 | Disk utilization. | |
1113 | .RE | |
d1429b5c | 1114 | .PD |
d60e92d1 AC |
1115 | .SH TERSE OUTPUT |
1116 | If the \fB\-\-minimal\fR option is given, the results will be printed in a | |
562c2d2f DN |
1117 | semicolon-delimited format suitable for scripted use - a job description |
1118 | (if provided) follows on a new line. Note that the first | |
525c2bfa JA |
1119 | number in the line is the version number. If the output has to be changed |
1120 | for some reason, this number will be incremented by 1 to signify that | |
1121 | change. The fields are: | |
d60e92d1 AC |
1122 | .P |
1123 | .RS | |
525c2bfa | 1124 | .B version, jobname, groupid, error |
d60e92d1 AC |
1125 | .P |
1126 | Read status: | |
1127 | .RS | |
312b4af2 | 1128 | .B Total I/O \fR(KB)\fP, bandwidth \fR(KB/s)\fP, IOPS, runtime \fR(ms)\fP |
d60e92d1 AC |
1129 | .P |
1130 | Submission latency: | |
1131 | .RS | |
1132 | .B min, max, mean, standard deviation | |
1133 | .RE | |
1134 | Completion latency: | |
1135 | .RS | |
1136 | .B min, max, mean, standard deviation | |
1137 | .RE | |
1db92cb6 JA |
1138 | Completion latency percentiles (20 fields): |
1139 | .RS | |
1140 | .B Xth percentile=usec | |
1141 | .RE | |
525c2bfa JA |
1142 | Total latency: |
1143 | .RS | |
1144 | .B min, max, mean, standard deviation | |
1145 | .RE | |
d60e92d1 AC |
1146 | Bandwidth: |
1147 | .RS | |
1148 | .B min, max, aggregate percentage of total, mean, standard deviation | |
1149 | .RE | |
1150 | .RE | |
1151 | .P | |
1152 | Write status: | |
1153 | .RS | |
312b4af2 | 1154 | .B Total I/O \fR(KB)\fP, bandwidth \fR(KB/s)\fP, IOPS, runtime \fR(ms)\fP |
d60e92d1 AC |
1155 | .P |
1156 | Submission latency: | |
1157 | .RS | |
1158 | .B min, max, mean, standard deviation | |
1159 | .RE | |
1160 | Completion latency: | |
1161 | .RS | |
1162 | .B min, max, mean, standard deviation | |
1163 | .RE | |
1db92cb6 JA |
1164 | Completion latency percentiles (20 fields): |
1165 | .RS | |
1166 | .B Xth percentile=usec | |
1167 | .RE | |
525c2bfa JA |
1168 | Total latency: |
1169 | .RS | |
1170 | .B min, max, mean, standard deviation | |
1171 | .RE | |
d60e92d1 AC |
1172 | Bandwidth: |
1173 | .RS | |
1174 | .B min, max, aggregate percentage of total, mean, standard deviation | |
1175 | .RE | |
1176 | .RE | |
1177 | .P | |
d1429b5c | 1178 | CPU usage: |
d60e92d1 | 1179 | .RS |
bd2626f0 | 1180 | .B user, system, context switches, major page faults, minor page faults |
d60e92d1 AC |
1181 | .RE |
1182 | .P | |
1183 | IO depth distribution: | |
1184 | .RS | |
1185 | .B <=1, 2, 4, 8, 16, 32, >=64 | |
1186 | .RE | |
1187 | .P | |
562c2d2f | 1188 | IO latency distribution: |
d60e92d1 | 1189 | .RS |
562c2d2f DN |
1190 | Microseconds: |
1191 | .RS | |
1192 | .B <=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000 | |
1193 | .RE | |
1194 | Milliseconds: | |
1195 | .RS | |
1196 | .B <=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000, 2000, >=2000 | |
1197 | .RE | |
1198 | .RE | |
1199 | .P | |
f2f788dd JA |
1200 | Disk utilization (1 for each disk used): |
1201 | .RS | |
1202 | .B name, read ios, write ios, read merges, write merges, read ticks, write ticks, read in-queue time, write in-queue time, disk utilization percentage | |
1203 | .RE | |
1204 | .P | |
5982a925 | 1205 | Error Info (dependent on continue_on_error, default off): |
562c2d2f DN |
1206 | .RS |
1207 | .B total # errors, first error code | |
d60e92d1 AC |
1208 | .RE |
1209 | .P | |
562c2d2f | 1210 | .B text description (if provided in config - appears on newline) |
d60e92d1 | 1211 | .RE |
49da1240 JA |
1212 | .SH CLIENT / SERVER |
1213 | Normally you would run fio as a stand-alone application on the machine | |
1214 | where the IO workload should be generated. However, it is also possible to | |
1215 | run the frontend and backend of fio separately. This makes it possible to | |
1216 | have a fio server running on the machine(s) where the IO workload should | |
1217 | be running, while controlling it from another machine. | |
1218 | ||
1219 | To start the server, you would do: | |
1220 | ||
1221 | \fBfio \-\-server=args\fR | |
1222 | ||
1223 | on that machine, where args defines what fio listens to. The arguments | |
1224 | are of the form 'type:hostname or IP:port'. 'type' is either 'ip' for | |
1225 | TCP/IP, or 'sock' for a local unix domain socket. 'hostname' is either | |
1226 | a hostname or IP address, and 'port' is the port to listen to (only valid | |
1227 | for TCP/IP, not a local socket). Some examples: | |
1228 | ||
1229 | 1) fio --server | |
1230 | ||
1231 | Start a fio server, listening on all interfaces on the default port (8765). | |
1232 | ||
1233 | 2) fio --server=ip:hostname:4444 | |
1234 | ||
1235 | Start a fio server, listening on IP belonging to hostname and on port 4444. | |
1236 | ||
1237 | 3) fio --server=:4444 | |
1238 | ||
1239 | Start a fio server, listening on all interfaces on port 4444. | |
1240 | ||
1241 | 4) fio --server=1.2.3.4 | |
1242 | ||
1243 | Start a fio server, listening on IP 1.2.3.4 on the default port. | |
1244 | ||
1245 | 5) fio --server=sock:/tmp/fio.sock | |
1246 | ||
1247 | Start a fio server, listening on the local socket /tmp/fio.sock. | |
1248 | ||
1249 | When a server is running, you can connect to it from a client. The client | |
1250 | is run with: | |
1251 | ||
1252 | fio --local-args --client=server --remote-args <job file(s)> | |
1253 | ||
1254 | where --local-args are arguments that are local to the client where it is | |
1255 | running, 'server' is the connect string, and --remote-args and <job file(s)> | |
1256 | are sent to the server. The 'server' string follows the same format as it | |
1257 | does on the server side, to allow IP/hostname/socket and port strings. | |
1258 | You can connect to multiple clients as well, to do that you could run: | |
1259 | ||
1260 | fio --client=server2 --client=server2 <job file(s)> | |
d60e92d1 | 1261 | .SH AUTHORS |
49da1240 | 1262 | |
d60e92d1 | 1263 | .B fio |
aa58d252 JA |
1264 | was written by Jens Axboe <jens.axboe@oracle.com>, |
1265 | now Jens Axboe <jaxboe@fusionio.com>. | |
d1429b5c AC |
1266 | .br |
1267 | This man page was written by Aaron Carroll <aaronc@cse.unsw.edu.au> based | |
d60e92d1 AC |
1268 | on documentation by Jens Axboe. |
1269 | .SH "REPORTING BUGS" | |
482900c9 | 1270 | Report bugs to the \fBfio\fR mailing list <fio@vger.kernel.org>. |
d1429b5c | 1271 | See \fBREADME\fR. |
d60e92d1 | 1272 | .SH "SEE ALSO" |
d1429b5c AC |
1273 | For further documentation see \fBHOWTO\fR and \fBREADME\fR. |
1274 | .br | |
1275 | Sample jobfiles are available in the \fBexamples\fR directory. | |
d60e92d1 | 1276 |