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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 | |
15 | .BI \-\-output \fR=\fPfilename | |
16 | Write output to \fIfilename\fR. | |
17 | .TP | |
18 | .BI \-\-timeout \fR=\fPtimeout | |
19 | Limit run time to \fItimeout\fR seconds. | |
20 | .TP | |
21 | .B \-\-latency\-log | |
22 | Generate per-job latency logs. | |
23 | .TP | |
24 | .B \-\-bandwidth\-log | |
25 | Generate per-job bandwidth logs. | |
26 | .TP | |
27 | .B \-\-minimal | |
d1429b5c | 28 | Print statistics in a terse, semicolon-delimited format. |
d60e92d1 AC |
29 | .TP |
30 | .BI \-\-showcmd \fR=\fPjobfile | |
31 | Convert \fIjobfile\fR to a set of command-line options. | |
32 | .TP | |
33 | .B \-\-readonly | |
34 | Enable read-only safety checks. | |
35 | .TP | |
36 | .BI \-\-eta \fR=\fPwhen | |
37 | Specifies when real-time ETA estimate should be printed. \fIwhen\fR may | |
38 | be one of `always', `never' or `auto'. | |
39 | .TP | |
c0a5d35e AC |
40 | .BI \-\-section \fR=\fPsec |
41 | Only run section \fIsec\fR from job file. | |
42 | .TP | |
d60e92d1 AC |
43 | .BI \-\-cmdhelp \fR=\fPcommand |
44 | Print help information for \fIcommand\fR. May be `all' for all commands. | |
45 | .TP | |
9183788d JA |
46 | .BI \-\-debug \fR=\fPtype |
47 | Enable verbose tracing of various fio actions. May be `all' for all types | |
48 | or individual types seperated by a comma (eg --debug=io,file). `help' will | |
49 | list all available tracing options. | |
50 | .TP | |
d60e92d1 AC |
51 | .B \-\-help |
52 | Display usage information and exit. | |
53 | .TP | |
54 | .B \-\-version | |
55 | Display version information and exit. | |
56 | .SH "JOB FILE FORMAT" | |
57 | Job files are in `ini' format. They consist of one or more | |
58 | job definitions, which begin with a job name in square brackets and | |
59 | extend to the next job name. The job name can be any ASCII string | |
60 | except `global', which has a special meaning. Following the job name is | |
61 | a sequence of zero or more parameters, one per line, that define the | |
62 | behavior of the job. Any line starting with a `;' or `#' character is | |
d1429b5c | 63 | considered a comment and ignored. |
d9956b64 AC |
64 | .P |
65 | If \fIjobfile\fR is specified as `-', the job file will be read from | |
66 | standard input. | |
d60e92d1 AC |
67 | .SS "Global Section" |
68 | The global section contains default parameters for jobs specified in the | |
69 | job file. A job is only affected by global sections residing above it, | |
70 | and there may be any number of global sections. Specific job definitions | |
71 | may override any parameter set in global sections. | |
72 | .SH "JOB PARAMETERS" | |
73 | .SS Types | |
74 | Some parameters may take arguments of a specific type. The types used are: | |
75 | .TP | |
76 | .I str | |
77 | String: a sequence of alphanumeric characters. | |
78 | .TP | |
79 | .I int | |
d60e92d1 AC |
80 | SI integer: a whole number, possibly containing a suffix denoting the base unit |
81 | of the value. Accepted suffixes are `k', 'M' and 'G', denoting kilo (1024), | |
f7fa2653 JA |
82 | mega (1024*1024) and giga (1024*1024*1024) respectively. If prefixed with '0x', |
83 | the value is assumed to be base 16 (hexadecimal). | |
d60e92d1 AC |
84 | .TP |
85 | .I bool | |
86 | Boolean: a true or false value. `0' denotes false, `1' denotes true. | |
87 | .TP | |
88 | .I irange | |
89 | Integer range: a range of integers specified in the format | |
d1429b5c AC |
90 | \fIlower\fR:\fIupper\fR or \fIlower\fR\-\fIupper\fR. \fIlower\fR and |
91 | \fIupper\fR may contain a suffix as described above. If an option allows two | |
92 | sets of ranges, they are separated with a `,' or `/' character. For example: | |
93 | `8\-8k/8M\-4G'. | |
d60e92d1 AC |
94 | .SS "Parameter List" |
95 | .TP | |
96 | .BI name \fR=\fPstr | |
d9956b64 | 97 | May be used to override the job name. On the command line, this parameter |
d60e92d1 AC |
98 | has the special purpose of signalling the start of a new job. |
99 | .TP | |
100 | .BI description \fR=\fPstr | |
101 | Human-readable description of the job. It is printed when the job is run, but | |
102 | otherwise has no special purpose. | |
103 | .TP | |
104 | .BI directory \fR=\fPstr | |
105 | Prefix filenames with this directory. Used to place files in a location other | |
106 | than `./'. | |
107 | .TP | |
108 | .BI filename \fR=\fPstr | |
109 | .B fio | |
110 | normally makes up a file name based on the job name, thread number, and file | |
d1429b5c AC |
111 | number. If you want to share files between threads in a job or several jobs, |
112 | specify a \fIfilename\fR for each of them to override the default. If the I/O | |
113 | engine used is `net', \fIfilename\fR is the host and port to connect to in the | |
114 | format \fIhost\fR/\fIport\fR. If the I/O engine is file-based, you can specify | |
115 | a number of files by separating the names with a `:' character. `\-' is a | |
116 | reserved name, meaning stdin or stdout, depending on the read/write direction | |
117 | set. | |
d60e92d1 | 118 | .TP |
3ce9dcaf JA |
119 | .BI lockfile \fR=\fPstr |
120 | Fio defaults to not locking any files before it does IO to them. If a file or | |
121 | file descriptor is shared, fio can serialize IO to that file to make the end | |
122 | result consistent. This is usual for emulating real workloads that share files. | |
123 | The lock modes are: | |
124 | .RS | |
125 | .RS | |
126 | .TP | |
127 | .B none | |
128 | No locking. This is the default. | |
129 | .TP | |
130 | .B exclusive | |
131 | Only one thread or process may do IO at the time, excluding all others. | |
132 | .TP | |
133 | .B readwrite | |
134 | Read-write locking on the file. Many readers may access the file at the same | |
135 | time, but writes get exclusive access. | |
136 | .RE | |
137 | .P | |
138 | The option may be post-fixed with a lock batch number. If set, then each | |
139 | thread/process may do that amount of IOs to the file before giving up the lock. | |
140 | Since lock acquisition is expensive, batching the lock/unlocks will speed up IO. | |
141 | .RE | |
142 | .P | |
d60e92d1 AC |
143 | .BI opendir \fR=\fPstr |
144 | Recursively open any files below directory \fIstr\fR. | |
145 | .TP | |
146 | .BI readwrite \fR=\fPstr "\fR,\fP rw" \fR=\fPstr | |
147 | Type of I/O pattern. Accepted values are: | |
148 | .RS | |
149 | .RS | |
150 | .TP | |
151 | .B read | |
d1429b5c | 152 | Sequential reads. |
d60e92d1 AC |
153 | .TP |
154 | .B write | |
d1429b5c | 155 | Sequential writes. |
d60e92d1 AC |
156 | .TP |
157 | .B randread | |
d1429b5c | 158 | Random reads. |
d60e92d1 AC |
159 | .TP |
160 | .B randwrite | |
d1429b5c | 161 | Random writes. |
d60e92d1 AC |
162 | .TP |
163 | .B rw | |
d1429b5c | 164 | Mixed sequential reads and writes. |
d60e92d1 AC |
165 | .TP |
166 | .B randrw | |
d1429b5c | 167 | Mixed random reads and writes. |
d60e92d1 AC |
168 | .RE |
169 | .P | |
d1429b5c AC |
170 | For mixed I/O, the default split is 50/50. For random I/O, the number of I/Os |
171 | to perform before getting a new offset can be specified by appending | |
172 | `:\fIint\fR' to the pattern type. The default is 1. | |
d60e92d1 AC |
173 | .RE |
174 | .TP | |
175 | .BI randrepeat \fR=\fPbool | |
176 | Seed the random number generator in a predictable way so results are repeatable | |
d1429b5c | 177 | across runs. Default: true. |
d60e92d1 AC |
178 | .TP |
179 | .BI fadvise_hint \fR=\fPbool | |
d1429b5c AC |
180 | Disable use of \fIposix_fadvise\fR\|(2) to advise the kernel what I/O patterns |
181 | are likely to be issued. Default: true. | |
d60e92d1 | 182 | .TP |
f7fa2653 | 183 | .BI size \fR=\fPint |
d60e92d1 AC |
184 | Total size of I/O for this job. \fBfio\fR will run until this many bytes have |
185 | been transfered, unless limited by other options (\fBruntime\fR, for instance). | |
186 | Unless \fBnr_files\fR and \fBfilesize\fR options are given, this amount will be | |
187 | divided between the available files for the job. | |
188 | .TP | |
3ce9dcaf JA |
189 | .BI fill_device \fR=\fPbool |
190 | Sets size to something really large and waits for ENOSPC (no space left on | |
191 | device) as the terminating condition. Only makes sense with sequential write. | |
192 | For a read workload, the mount point will be filled first then IO started on | |
193 | the result. | |
194 | .TP | |
d60e92d1 AC |
195 | .BI filesize \fR=\fPirange |
196 | Individual file sizes. May be a range, in which case \fBfio\fR will select sizes | |
d1429b5c AC |
197 | for files at random within the given range, limited to \fBsize\fR in total (if |
198 | that is given). If \fBfilesize\fR is not specified, each created file is the | |
199 | same size. | |
d60e92d1 | 200 | .TP |
f7fa2653 | 201 | .BI blocksize \fR=\fPint[,int] "\fR,\fB bs" \fR=\fPint[,int] |
d60e92d1 AC |
202 | Block size for I/O units. Default: 4k. Values for reads and writes can be |
203 | specified seperately in the format \fIread\fR,\fIwrite\fR, either of | |
204 | which may be empty to leave that value at its default. | |
205 | .TP | |
9183788d | 206 | .BI blocksize_range \fR=\fPirange[,irange] "\fR,\fB bsrange" \fR=\fPirange[,irange] |
d1429b5c AC |
207 | Specify a range of I/O block sizes. The issued I/O unit will always be a |
208 | multiple of the minimum size, unless \fBblocksize_unaligned\fR is set. Applies | |
9183788d JA |
209 | to both reads and writes if only one range is given, but can be specified |
210 | seperately with a comma seperating the values. Example: bsrange=1k-4k,2k-8k. | |
211 | Also (see \fBblocksize\fR). | |
212 | .TP | |
213 | .BI bssplit \fR=\fPstr | |
214 | This option allows even finer grained control of the block sizes issued, | |
215 | not just even splits between them. With this option, you can weight various | |
216 | block sizes for exact control of the issued IO for a job that has mixed | |
217 | block sizes. The format of the option is bssplit=blocksize/percentage, | |
218 | optionally adding as many definitions as needed seperated by a colon. | |
219 | Example: bssplit=4k/10:64k/50:32k/40 would issue 50% 64k blocks, 10% 4k | |
c83cdd3e JA |
220 | blocks and 40% 32k blocks. \fBbssplit\fR also supports giving separate |
221 | splits to reads and writes. The format is identical to what the | |
222 | \fBbs\fR option accepts, the read and write parts are separated with a | |
223 | comma. | |
d60e92d1 AC |
224 | .TP |
225 | .B blocksize_unaligned\fR,\fP bs_unaligned | |
d1429b5c AC |
226 | If set, any size in \fBblocksize_range\fR may be used. This typically won't |
227 | work with direct I/O, as that normally requires sector alignment. | |
d60e92d1 | 228 | .TP |
2b7a01d0 | 229 | .BI blockalign \fR=\fPint[,int] "\fR,\fB ba" \fR=\fPint[,int] |
639ce0f3 MS |
230 | At what boundary to align random IO offsets. Defaults to the same as 'blocksize' |
231 | the minimum blocksize given. Minimum alignment is typically 512b | |
2b7a01d0 JA |
232 | for using direct IO, though it usually depends on the hardware block size. |
233 | This option is mutually exclusive with using a random map for files, so it | |
234 | will turn off that option. | |
43602667 | 235 | .TP |
d60e92d1 AC |
236 | .B zero_buffers |
237 | Initialise buffers with all zeros. Default: fill buffers with random data. | |
238 | .TP | |
901bb994 JA |
239 | .B refill_buffers |
240 | If this option is given, fio will refill the IO buffers on every submit. The | |
241 | default is to only fill it at init time and reuse that data. Only makes sense | |
242 | if zero_buffers isn't specified, naturally. If data verification is enabled, | |
243 | refill_buffers is also automatically enabled. | |
244 | .TP | |
d60e92d1 AC |
245 | .BI nrfiles \fR=\fPint |
246 | Number of files to use for this job. Default: 1. | |
247 | .TP | |
248 | .BI openfiles \fR=\fPint | |
249 | Number of files to keep open at the same time. Default: \fBnrfiles\fR. | |
250 | .TP | |
251 | .BI file_service_type \fR=\fPstr | |
252 | Defines how files to service are selected. The following types are defined: | |
253 | .RS | |
254 | .RS | |
255 | .TP | |
256 | .B random | |
257 | Choose a file at random | |
258 | .TP | |
259 | .B roundrobin | |
260 | Round robin over open files (default). | |
6b7f6851 JA |
261 | .B sequential |
262 | Do each file in the set sequentially. | |
d60e92d1 AC |
263 | .RE |
264 | .P | |
265 | The number of I/Os to issue before switching a new file can be specified by | |
266 | appending `:\fIint\fR' to the service type. | |
267 | .RE | |
268 | .TP | |
269 | .BI ioengine \fR=\fPstr | |
270 | Defines how the job issues I/O. The following types are defined: | |
271 | .RS | |
272 | .RS | |
273 | .TP | |
274 | .B sync | |
275 | Basic \fIread\fR\|(2) or \fIwrite\fR\|(2) I/O. \fIfseek\fR\|(2) is used to | |
276 | position the I/O location. | |
277 | .TP | |
a31041ea | 278 | .B psync |
279 | Basic \fIpread\fR\|(2) or \fIpwrite\fR\|(2) I/O. | |
280 | .TP | |
9183788d JA |
281 | .B vsync |
282 | Basic \fIreadv\fR\|(2) or \fIwritev\fR\|(2) I/O. Will emulate queuing by | |
283 | coalescing adjacents IOs into a single submission. | |
284 | .TP | |
d60e92d1 AC |
285 | .B libaio |
286 | Linux native asynchronous I/O. | |
287 | .TP | |
288 | .B posixaio | |
289 | glibc POSIX asynchronous I/O using \fIaio_read\fR\|(3) and \fIaio_write\fR\|(3). | |
290 | .TP | |
291 | .B mmap | |
d1429b5c AC |
292 | File is memory mapped with \fImmap\fR\|(2) and data copied using |
293 | \fImemcpy\fR\|(3). | |
d60e92d1 AC |
294 | .TP |
295 | .B splice | |
d1429b5c AC |
296 | \fIsplice\fR\|(2) is used to transfer the data and \fIvmsplice\fR\|(2) to |
297 | transfer data from user-space to the kernel. | |
d60e92d1 AC |
298 | .TP |
299 | .B syslet-rw | |
300 | Use the syslet system calls to make regular read/write asynchronous. | |
301 | .TP | |
302 | .B sg | |
303 | SCSI generic sg v3 I/O. May be either synchronous using the SG_IO ioctl, or if | |
d1429b5c AC |
304 | the target is an sg character device, we use \fIread\fR\|(2) and |
305 | \fIwrite\fR\|(2) for asynchronous I/O. | |
d60e92d1 AC |
306 | .TP |
307 | .B null | |
308 | Doesn't transfer any data, just pretends to. Mainly used to exercise \fBfio\fR | |
309 | itself and for debugging and testing purposes. | |
310 | .TP | |
311 | .B net | |
312 | Transfer over the network. \fBfilename\fR must be set appropriately to | |
313 | `\fIhost\fR/\fIport\fR' regardless of data direction. If receiving, only the | |
314 | \fIport\fR argument is used. | |
315 | .TP | |
316 | .B netsplice | |
317 | Like \fBnet\fR, but uses \fIsplice\fR\|(2) and \fIvmsplice\fR\|(2) to map data | |
318 | and send/receive. | |
319 | .TP | |
53aec0a4 | 320 | .B cpuio |
d60e92d1 AC |
321 | Doesn't transfer any data, but burns CPU cycles according to \fBcpuload\fR and |
322 | \fBcpucycles\fR parameters. | |
323 | .TP | |
324 | .B guasi | |
325 | The GUASI I/O engine is the Generic Userspace Asynchronous Syscall Interface | |
326 | approach to asycnronous I/O. | |
d1429b5c AC |
327 | .br |
328 | See <http://www.xmailserver.org/guasi\-lib.html>. | |
d60e92d1 AC |
329 | .TP |
330 | .B external | |
331 | Loads an external I/O engine object file. Append the engine filename as | |
332 | `:\fIenginepath\fR'. | |
333 | .RE | |
334 | .RE | |
335 | .TP | |
336 | .BI iodepth \fR=\fPint | |
337 | Number of I/O units to keep in flight against the file. Default: 1. | |
338 | .TP | |
339 | .BI iodepth_batch \fR=\fPint | |
340 | Number of I/Os to submit at once. Default: \fBiodepth\fR. | |
341 | .TP | |
3ce9dcaf JA |
342 | .BI iodepth_batch_complete \fR=\fPint |
343 | This defines how many pieces of IO to retrieve at once. It defaults to 1 which | |
344 | means that we'll ask for a minimum of 1 IO in the retrieval process from the | |
345 | kernel. The IO retrieval will go on until we hit the limit set by | |
346 | \fBiodepth_low\fR. If this variable is set to 0, then fio will always check for | |
347 | completed events before queuing more IO. This helps reduce IO latency, at the | |
348 | cost of more retrieval system calls. | |
349 | .TP | |
d60e92d1 AC |
350 | .BI iodepth_low \fR=\fPint |
351 | Low watermark indicating when to start filling the queue again. Default: | |
352 | \fBiodepth\fR. | |
353 | .TP | |
354 | .BI direct \fR=\fPbool | |
355 | If true, use non-buffered I/O (usually O_DIRECT). Default: false. | |
356 | .TP | |
357 | .BI buffered \fR=\fPbool | |
358 | If true, use buffered I/O. This is the opposite of the \fBdirect\fR parameter. | |
359 | Default: true. | |
360 | .TP | |
f7fa2653 | 361 | .BI offset \fR=\fPint |
d60e92d1 AC |
362 | Offset in the file to start I/O. Data before the offset will not be touched. |
363 | .TP | |
364 | .BI fsync \fR=\fPint | |
d1429b5c AC |
365 | How many I/Os to perform before issuing an \fBfsync\fR\|(2) of dirty data. If |
366 | 0, don't sync. Default: 0. | |
d60e92d1 AC |
367 | .TP |
368 | .BI overwrite \fR=\fPbool | |
d1429b5c | 369 | If writing, setup the file first and do overwrites. Default: false. |
d60e92d1 AC |
370 | .TP |
371 | .BI end_fsync \fR=\fPbool | |
d1429b5c | 372 | Sync file contents when job exits. Default: false. |
d60e92d1 AC |
373 | .TP |
374 | .BI fsync_on_close \fR=\fPbool | |
375 | If true, sync file contents on close. This differs from \fBend_fsync\fR in that | |
d1429b5c | 376 | it will happen on every close, not just at the end of the job. Default: false. |
d60e92d1 AC |
377 | .TP |
378 | .BI rwmixcycle \fR=\fPint | |
379 | How many milliseconds before switching between reads and writes for a mixed | |
380 | workload. Default: 500ms. | |
381 | .TP | |
382 | .BI rwmixread \fR=\fPint | |
383 | Percentage of a mixed workload that should be reads. Default: 50. | |
384 | .TP | |
385 | .BI rwmixwrite \fR=\fPint | |
d1429b5c | 386 | Percentage of a mixed workload that should be writes. If \fBrwmixread\fR and |
c35dd7a6 JA |
387 | \fBrwmixwrite\fR are given and do not sum to 100%, the latter of the two |
388 | overrides the first. This may interfere with a given rate setting, if fio is | |
389 | asked to limit reads or writes to a certain rate. If that is the case, then | |
390 | the distribution may be skewed. Default: 50. | |
d60e92d1 AC |
391 | .TP |
392 | .B norandommap | |
393 | Normally \fBfio\fR will cover every block of the file when doing random I/O. If | |
394 | this parameter is given, a new offset will be chosen without looking at past | |
395 | I/O history. This parameter is mutually exclusive with \fBverify\fR. | |
396 | .TP | |
3ce9dcaf JA |
397 | .B softrandommap |
398 | See \fBnorandommap\fR. If fio runs with the random block map enabled and it | |
399 | fails to allocate the map, if this option is set it will continue without a | |
400 | random block map. As coverage will not be as complete as with random maps, this | |
401 | option is disabled by default. | |
402 | .TP | |
d60e92d1 AC |
403 | .BI nice \fR=\fPint |
404 | Run job with given nice value. See \fInice\fR\|(2). | |
405 | .TP | |
406 | .BI prio \fR=\fPint | |
407 | Set I/O priority value of this job between 0 (highest) and 7 (lowest). See | |
408 | \fIionice\fR\|(1). | |
409 | .TP | |
410 | .BI prioclass \fR=\fPint | |
411 | Set I/O priority class. See \fIionice\fR\|(1). | |
412 | .TP | |
413 | .BI thinktime \fR=\fPint | |
414 | Stall job for given number of microseconds between issuing I/Os. | |
415 | .TP | |
416 | .BI thinktime_spin \fR=\fPint | |
417 | Pretend to spend CPU time for given number of microseconds, sleeping the rest | |
418 | of the time specified by \fBthinktime\fR. Only valid if \fBthinktime\fR is set. | |
419 | .TP | |
420 | .BI thinktime_blocks \fR=\fPint | |
421 | Number of blocks to issue before waiting \fBthinktime\fR microseconds. | |
422 | Default: 1. | |
423 | .TP | |
424 | .BI rate \fR=\fPint | |
c35dd7a6 JA |
425 | Cap bandwidth used by this job. The number is in bytes/sec, the normal postfix |
426 | rules apply. You can use \fBrate\fR=500k to limit reads and writes to 500k each, | |
427 | or you can specify read and writes separately. Using \fBrate\fR=1m,500k would | |
428 | limit reads to 1MB/sec and writes to 500KB/sec. Capping only reads or writes | |
429 | can be done with \fBrate\fR=,500k or \fBrate\fR=500k,. The former will only | |
430 | limit writes (to 500KB/sec), the latter will only limit reads. | |
d60e92d1 AC |
431 | .TP |
432 | .BI ratemin \fR=\fPint | |
433 | Tell \fBfio\fR to do whatever it can to maintain at least the given bandwidth. | |
c35dd7a6 JA |
434 | Failing to meet this requirement will cause the job to exit. The same format |
435 | as \fBrate\fR is used for read vs write separation. | |
d60e92d1 AC |
436 | .TP |
437 | .BI rate_iops \fR=\fPint | |
c35dd7a6 JA |
438 | Cap the bandwidth to this number of IOPS. Basically the same as rate, just |
439 | specified independently of bandwidth. The same format as \fBrate\fR is used for | |
440 | read vs write seperation. If \fBblocksize\fR is a range, the smallest block | |
441 | size is used as the metric. | |
d60e92d1 AC |
442 | .TP |
443 | .BI rate_iops_min \fR=\fPint | |
c35dd7a6 JA |
444 | If this rate of I/O is not met, the job will exit. The same format as \fBrate\fR |
445 | is used for read vs write seperation. | |
d60e92d1 AC |
446 | .TP |
447 | .BI ratecycle \fR=\fPint | |
448 | Average bandwidth for \fBrate\fR and \fBratemin\fR over this number of | |
449 | milliseconds. Default: 1000ms. | |
450 | .TP | |
451 | .BI cpumask \fR=\fPint | |
452 | Set CPU affinity for this job. \fIint\fR is a bitmask of allowed CPUs the job | |
453 | may run on. See \fBsched_setaffinity\fR\|(2). | |
454 | .TP | |
455 | .BI cpus_allowed \fR=\fPstr | |
456 | Same as \fBcpumask\fR, but allows a comma-delimited list of CPU numbers. | |
457 | .TP | |
458 | .BI startdelay \fR=\fPint | |
459 | Delay start of job for the specified number of seconds. | |
460 | .TP | |
461 | .BI runtime \fR=\fPint | |
462 | Terminate processing after the specified number of seconds. | |
463 | .TP | |
464 | .B time_based | |
465 | If given, run for the specified \fBruntime\fR duration even if the files are | |
466 | completely read or written. The same workload will be repeated as many times | |
467 | as \fBruntime\fR allows. | |
468 | .TP | |
901bb994 JA |
469 | .BI ramp_time \fR=\fPint |
470 | If set, fio will run the specified workload for this amount of time before | |
471 | logging any performance numbers. Useful for letting performance settle before | |
472 | logging results, thus minimizing the runtime required for stable results. Note | |
c35dd7a6 JA |
473 | that the \fBramp_time\fR is considered lead in time for a job, thus it will |
474 | increase the total runtime if a special timeout or runtime is specified. | |
901bb994 | 475 | .TP |
d60e92d1 AC |
476 | .BI invalidate \fR=\fPbool |
477 | Invalidate buffer-cache for the file prior to starting I/O. Default: true. | |
478 | .TP | |
479 | .BI sync \fR=\fPbool | |
480 | Use synchronous I/O for buffered writes. For the majority of I/O engines, | |
d1429b5c | 481 | this means using O_SYNC. Default: false. |
d60e92d1 AC |
482 | .TP |
483 | .BI iomem \fR=\fPstr "\fR,\fP mem" \fR=\fPstr | |
484 | Allocation method for I/O unit buffer. Allowed values are: | |
485 | .RS | |
486 | .RS | |
487 | .TP | |
488 | .B malloc | |
489 | Allocate memory with \fImalloc\fR\|(3). | |
490 | .TP | |
491 | .B shm | |
492 | Use shared memory buffers allocated through \fIshmget\fR\|(2). | |
493 | .TP | |
494 | .B shmhuge | |
495 | Same as \fBshm\fR, but use huge pages as backing. | |
496 | .TP | |
497 | .B mmap | |
498 | Use \fImmap\fR\|(2) for allocation. Uses anonymous memory unless a filename | |
499 | is given after the option in the format `:\fIfile\fR'. | |
500 | .TP | |
501 | .B mmaphuge | |
502 | Same as \fBmmap\fR, but use huge files as backing. | |
503 | .RE | |
504 | .P | |
505 | The amount of memory allocated is the maximum allowed \fBblocksize\fR for the | |
506 | job multiplied by \fBiodepth\fR. For \fBshmhuge\fR or \fBmmaphuge\fR to work, | |
507 | the system must have free huge pages allocated. \fBmmaphuge\fR also needs to | |
508 | have hugetlbfs mounted, and \fIfile\fR must point there. | |
509 | .RE | |
510 | .TP | |
f7fa2653 | 511 | .BI hugepage\-size \fR=\fPint |
d60e92d1 AC |
512 | Defines the size of a huge page. Must be at least equal to the system setting. |
513 | Should be a multiple of 1MiB. Default: 4MiB. | |
514 | .TP | |
515 | .B exitall | |
516 | Terminate all jobs when one finishes. Default: wait for each job to finish. | |
517 | .TP | |
518 | .BI bwavgtime \fR=\fPint | |
519 | Average bandwidth calculations over the given time in milliseconds. Default: | |
520 | 500ms. | |
521 | .TP | |
522 | .BI create_serialize \fR=\fPbool | |
d1429b5c | 523 | If true, serialize file creation for the jobs. Default: true. |
d60e92d1 AC |
524 | .TP |
525 | .BI create_fsync \fR=\fPbool | |
526 | \fIfsync\fR\|(2) data file after creation. Default: true. | |
527 | .TP | |
6b7f6851 JA |
528 | .BI create_on_open \fR=\fPbool |
529 | If true, the files are not created until they are opened for IO by the job. | |
530 | .TP | |
e9f48479 JA |
531 | .BI pre_read \fR=\fPbool |
532 | If this is given, files will be pre-read into memory before starting the given | |
533 | IO operation. This will also clear the \fR \fBinvalidate\fR flag, since it is | |
534 | pointless to pre-read and then drop the cache. | |
535 | .TP | |
d60e92d1 AC |
536 | .BI unlink \fR=\fPbool |
537 | Unlink job files when done. Default: false. | |
538 | .TP | |
539 | .BI loops \fR=\fPint | |
540 | Specifies the number of iterations (runs of the same workload) of this job. | |
541 | Default: 1. | |
542 | .TP | |
543 | .BI do_verify \fR=\fPbool | |
544 | Run the verify phase after a write phase. Only valid if \fBverify\fR is set. | |
545 | Default: true. | |
546 | .TP | |
547 | .BI verify \fR=\fPstr | |
548 | Method of verifying file contents after each iteration of the job. Allowed | |
549 | values are: | |
550 | .RS | |
551 | .RS | |
552 | .TP | |
553 | .B md5 crc16 crc32 crc64 crc7 sha256 sha512 | |
554 | Store appropriate checksum in the header of each block. | |
555 | .TP | |
556 | .B meta | |
557 | Write extra information about each I/O (timestamp, block number, etc.). The | |
558 | block number is verified. | |
559 | .TP | |
560 | .B pattern | |
561 | Fill I/O buffers with a specific pattern that is used to verify. The pattern is | |
562 | specified by appending `:\fIint\fR' to the parameter. \fIint\fR cannot be larger | |
563 | than 32-bits. | |
564 | .TP | |
565 | .B null | |
566 | Pretend to verify. Used for testing internals. | |
567 | .RE | |
568 | .RE | |
569 | .TP | |
570 | .BI verify_sort \fR=\fPbool | |
571 | If true, written verify blocks are sorted if \fBfio\fR deems it to be faster to | |
572 | read them back in a sorted manner. Default: true. | |
573 | .TP | |
f7fa2653 | 574 | .BI verify_offset \fR=\fPint |
d60e92d1 | 575 | Swap the verification header with data somewhere else in the block before |
d1429b5c | 576 | writing. It is swapped back before verifying. |
d60e92d1 | 577 | .TP |
f7fa2653 | 578 | .BI verify_interval \fR=\fPint |
d60e92d1 AC |
579 | Write the verification header for this number of bytes, which should divide |
580 | \fBblocksize\fR. Default: \fBblocksize\fR. | |
581 | .TP | |
582 | .BI verify_fatal \fR=\fPbool | |
583 | If true, exit the job on the first observed verification failure. Default: | |
584 | false. | |
585 | .TP | |
586 | .B stonewall | |
d1429b5c | 587 | Wait for preceeding jobs in the job file to exit before starting this one. |
d60e92d1 AC |
588 | \fBstonewall\fR implies \fBnew_group\fR. |
589 | .TP | |
590 | .B new_group | |
591 | Start a new reporting group. If not given, all jobs in a file will be part | |
592 | of the same reporting group, unless separated by a stonewall. | |
593 | .TP | |
594 | .BI numjobs \fR=\fPint | |
595 | Number of clones (processes/threads performing the same workload) of this job. | |
596 | Default: 1. | |
597 | .TP | |
598 | .B group_reporting | |
599 | If set, display per-group reports instead of per-job when \fBnumjobs\fR is | |
600 | specified. | |
601 | .TP | |
602 | .B thread | |
603 | Use threads created with \fBpthread_create\fR\|(3) instead of processes created | |
604 | with \fBfork\fR\|(2). | |
605 | .TP | |
f7fa2653 | 606 | .BI zonesize \fR=\fPint |
d60e92d1 AC |
607 | Divide file into zones of the specified size in bytes. See \fBzoneskip\fR. |
608 | .TP | |
f7fa2653 | 609 | .BI zoneskip \fR=\fPint |
d1429b5c | 610 | Skip the specified number of bytes when \fBzonesize\fR bytes of data have been |
d60e92d1 AC |
611 | read. |
612 | .TP | |
613 | .BI write_iolog \fR=\fPstr | |
614 | Write the issued I/O patterns to the specified file. | |
615 | .TP | |
616 | .BI read_iolog \fR=\fPstr | |
617 | Replay the I/O patterns contained in the specified file generated by | |
618 | \fBwrite_iolog\fR, or may be a \fBblktrace\fR binary file. | |
619 | .TP | |
901bb994 JA |
620 | .B write_bw_log \fR=\fPstr |
621 | If given, write a bandwidth log of the jobs in this job file. Can be used to | |
622 | store data of the bandwidth of the jobs in their lifetime. The included | |
623 | fio_generate_plots script uses gnuplot to turn these text files into nice | |
624 | graphs. See \fBwrite_log_log\fR for behaviour of given filename. For this | |
625 | option, the postfix is _bw.log. | |
d60e92d1 AC |
626 | .TP |
627 | .B write_lat_log | |
901bb994 JA |
628 | Same as \fBwrite_bw_log\fR, but writes I/O completion latencies. If no |
629 | filename is given with this option, the default filename of "jobname_type.log" | |
630 | is used. Even if the filename is given, fio will still append the type of log. | |
631 | .TP | |
632 | .B disable_clat \fR=\fPbool | |
633 | Disable measurements of completion latency numbers. Useful only for cutting | |
634 | back the number of calls to gettimeofday, as that does impact performance at | |
635 | really high IOPS rates. Note that to really get rid of a large amount of these | |
636 | calls, this option must be used with disable_slat and disable_bw as well. | |
637 | .TP | |
638 | .B disable_slat \fR=\fPbool | |
639 | Disable measurements of submission latency numbers. See \fBdisable_clat\fR. | |
640 | .TP | |
641 | .B disable_bw_measurement \fR=\fPbool | |
642 | Disable measurements of throughput/bandwidth numbers. See \fBdisable_clat\fR. | |
d60e92d1 | 643 | .TP |
f7fa2653 | 644 | .BI lockmem \fR=\fPint |
d60e92d1 AC |
645 | Pin the specified amount of memory with \fBmlock\fR\|(2). Can be used to |
646 | simulate a smaller amount of memory. | |
647 | .TP | |
648 | .BI exec_prerun \fR=\fPstr | |
649 | Before running the job, execute the specified command with \fBsystem\fR\|(3). | |
650 | .TP | |
651 | .BI exec_postrun \fR=\fPstr | |
652 | Same as \fBexec_prerun\fR, but the command is executed after the job completes. | |
653 | .TP | |
654 | .BI ioscheduler \fR=\fPstr | |
655 | Attempt to switch the device hosting the file to the specified I/O scheduler. | |
656 | .TP | |
657 | .BI cpuload \fR=\fPint | |
658 | If the job is a CPU cycle-eater, attempt to use the specified percentage of | |
659 | CPU cycles. | |
660 | .TP | |
661 | .BI cpuchunks \fR=\fPint | |
662 | If the job is a CPU cycle-eater, split the load into cycles of the | |
663 | given time in milliseconds. | |
664 | .TP | |
665 | .BI disk_util \fR=\fPbool | |
d1429b5c | 666 | Generate disk utilization statistics if the platform supports it. Default: true. |
901bb994 JA |
667 | .TP |
668 | .BI gtod_reduce \fR=\fPbool | |
669 | Enable all of the gettimeofday() reducing options (disable_clat, disable_slat, | |
670 | disable_bw) plus reduce precision of the timeout somewhat to really shrink the | |
671 | gettimeofday() call count. With this option enabled, we only do about 0.4% of | |
672 | the gtod() calls we would have done if all time keeping was enabled. | |
673 | .TP | |
674 | .BI gtod_cpu \fR=\fPint | |
675 | Sometimes it's cheaper to dedicate a single thread of execution to just getting | |
676 | the current time. Fio (and databases, for instance) are very intensive on | |
677 | gettimeofday() calls. With this option, you can set one CPU aside for doing | |
678 | nothing but logging current time to a shared memory location. Then the other | |
679 | threads/processes that run IO workloads need only copy that segment, instead of | |
680 | entering the kernel with a gettimeofday() call. The CPU set aside for doing | |
681 | these time calls will be excluded from other uses. Fio will manually clear it | |
682 | from the CPU mask of other jobs. | |
f2bba182 RR |
683 | .TP |
684 | .BI continue_on_error \fR=\fPbool | |
685 | Normally fio will exit the job on the first observed failure. If this option is | |
686 | set, fio will continue the job when there is a 'non-fatal error' | |
687 | (\fBEIO\fR or \fBEILSEQ\fR) until the runtime is exceeded or the I/O size | |
688 | specified is completed. If this option is used, there are two more stats that | |
689 | are appended, the total error count and the first error. The error field given | |
690 | in the stats is the first error that was hit during the run. | |
d60e92d1 | 691 | .SH OUTPUT |
d1429b5c AC |
692 | While running, \fBfio\fR will display the status of the created jobs. For |
693 | example: | |
d60e92d1 | 694 | .RS |
d1429b5c | 695 | .P |
d60e92d1 AC |
696 | Threads: 1: [_r] [24.8% done] [ 13509/ 8334 kb/s] [eta 00h:01m:31s] |
697 | .RE | |
698 | .P | |
d1429b5c AC |
699 | The characters in the first set of brackets denote the current status of each |
700 | threads. The possible values are: | |
701 | .P | |
702 | .PD 0 | |
d60e92d1 AC |
703 | .RS |
704 | .TP | |
705 | .B P | |
706 | Setup but not started. | |
707 | .TP | |
708 | .B C | |
709 | Thread created. | |
710 | .TP | |
711 | .B I | |
712 | Initialized, waiting. | |
713 | .TP | |
714 | .B R | |
715 | Running, doing sequential reads. | |
716 | .TP | |
717 | .B r | |
718 | Running, doing random reads. | |
719 | .TP | |
720 | .B W | |
721 | Running, doing sequential writes. | |
722 | .TP | |
723 | .B w | |
724 | Running, doing random writes. | |
725 | .TP | |
726 | .B M | |
727 | Running, doing mixed sequential reads/writes. | |
728 | .TP | |
729 | .B m | |
730 | Running, doing mixed random reads/writes. | |
731 | .TP | |
732 | .B F | |
733 | Running, currently waiting for \fBfsync\fR\|(2). | |
734 | .TP | |
735 | .B V | |
736 | Running, verifying written data. | |
737 | .TP | |
738 | .B E | |
739 | Exited, not reaped by main thread. | |
740 | .TP | |
741 | .B \- | |
742 | Exited, thread reaped. | |
743 | .RE | |
d1429b5c | 744 | .PD |
d60e92d1 AC |
745 | .P |
746 | The second set of brackets shows the estimated completion percentage of | |
747 | the current group. The third set shows the read and write I/O rate, | |
748 | respectively. Finally, the estimated run time of the job is displayed. | |
749 | .P | |
750 | When \fBfio\fR completes (or is interrupted by Ctrl-C), it will show data | |
751 | for each thread, each group of threads, and each disk, in that order. | |
752 | .P | |
753 | Per-thread statistics first show the threads client number, group-id, and | |
754 | error code. The remaining figures are as follows: | |
755 | .RS | |
d60e92d1 AC |
756 | .TP |
757 | .B io | |
758 | Number of megabytes of I/O performed. | |
759 | .TP | |
760 | .B bw | |
761 | Average data rate (bandwidth). | |
762 | .TP | |
763 | .B runt | |
764 | Threads run time. | |
765 | .TP | |
766 | .B slat | |
767 | Submission latency minimum, maximum, average and standard deviation. This is | |
768 | the time it took to submit the I/O. | |
769 | .TP | |
770 | .B clat | |
771 | Completion latency minimum, maximum, average and standard deviation. This | |
772 | is the time between submission and completion. | |
773 | .TP | |
774 | .B bw | |
775 | Bandwidth minimum, maximum, percentage of aggregate bandwidth received, average | |
776 | and standard deviation. | |
777 | .TP | |
778 | .B cpu | |
779 | CPU usage statistics. Includes user and system time, number of context switches | |
780 | this thread went through and number of major and minor page faults. | |
781 | .TP | |
782 | .B IO depths | |
783 | Distribution of I/O depths. Each depth includes everything less than (or equal) | |
784 | to it, but greater than the previous depth. | |
785 | .TP | |
786 | .B IO issued | |
787 | Number of read/write requests issued, and number of short read/write requests. | |
788 | .TP | |
789 | .B IO latencies | |
790 | Distribution of I/O completion latencies. The numbers follow the same pattern | |
791 | as \fBIO depths\fR. | |
792 | .RE | |
d60e92d1 AC |
793 | .P |
794 | The group statistics show: | |
d1429b5c | 795 | .PD 0 |
d60e92d1 AC |
796 | .RS |
797 | .TP | |
798 | .B io | |
799 | Number of megabytes I/O performed. | |
800 | .TP | |
801 | .B aggrb | |
802 | Aggregate bandwidth of threads in the group. | |
803 | .TP | |
804 | .B minb | |
805 | Minimum average bandwidth a thread saw. | |
806 | .TP | |
807 | .B maxb | |
808 | Maximum average bandwidth a thread saw. | |
809 | .TP | |
810 | .B mint | |
d1429b5c | 811 | Shortest runtime of threads in the group. |
d60e92d1 AC |
812 | .TP |
813 | .B maxt | |
814 | Longest runtime of threads in the group. | |
815 | .RE | |
d1429b5c | 816 | .PD |
d60e92d1 AC |
817 | .P |
818 | Finally, disk statistics are printed with reads first: | |
d1429b5c | 819 | .PD 0 |
d60e92d1 AC |
820 | .RS |
821 | .TP | |
822 | .B ios | |
823 | Number of I/Os performed by all groups. | |
824 | .TP | |
825 | .B merge | |
826 | Number of merges in the I/O scheduler. | |
827 | .TP | |
828 | .B ticks | |
829 | Number of ticks we kept the disk busy. | |
830 | .TP | |
831 | .B io_queue | |
832 | Total time spent in the disk queue. | |
833 | .TP | |
834 | .B util | |
835 | Disk utilization. | |
836 | .RE | |
d1429b5c | 837 | .PD |
d60e92d1 AC |
838 | .SH TERSE OUTPUT |
839 | If the \fB\-\-minimal\fR option is given, the results will be printed in a | |
840 | semicolon-delimited format suitable for scripted use. The fields are: | |
841 | .P | |
842 | .RS | |
843 | .B jobname, groupid, error | |
844 | .P | |
845 | Read status: | |
846 | .RS | |
847 | .B KiB I/O, bandwidth \fR(KiB/s)\fP, runtime \fR(ms)\fP | |
848 | .P | |
849 | Submission latency: | |
850 | .RS | |
851 | .B min, max, mean, standard deviation | |
852 | .RE | |
853 | Completion latency: | |
854 | .RS | |
855 | .B min, max, mean, standard deviation | |
856 | .RE | |
857 | Bandwidth: | |
858 | .RS | |
859 | .B min, max, aggregate percentage of total, mean, standard deviation | |
860 | .RE | |
861 | .RE | |
862 | .P | |
863 | Write status: | |
864 | .RS | |
865 | .B KiB I/O, bandwidth \fR(KiB/s)\fP, runtime \fR(ms)\fP | |
866 | .P | |
867 | Submission latency: | |
868 | .RS | |
869 | .B min, max, mean, standard deviation | |
870 | .RE | |
871 | Completion latency: | |
872 | .RS | |
873 | .B min, max, mean, standard deviation | |
874 | .RE | |
875 | Bandwidth: | |
876 | .RS | |
877 | .B min, max, aggregate percentage of total, mean, standard deviation | |
878 | .RE | |
879 | .RE | |
880 | .P | |
d1429b5c | 881 | CPU usage: |
d60e92d1 | 882 | .RS |
bd2626f0 | 883 | .B user, system, context switches, major page faults, minor page faults |
d60e92d1 AC |
884 | .RE |
885 | .P | |
886 | IO depth distribution: | |
887 | .RS | |
888 | .B <=1, 2, 4, 8, 16, 32, >=64 | |
889 | .RE | |
890 | .P | |
891 | IO latency distribution (ms): | |
892 | .RS | |
893 | .B <=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000, >=2000 | |
894 | .RE | |
895 | .P | |
896 | .B text description | |
897 | .RE | |
898 | .SH AUTHORS | |
899 | .B fio | |
900 | was written by Jens Axboe <jens.axboe@oracle.com>. | |
d1429b5c AC |
901 | .br |
902 | This man page was written by Aaron Carroll <aaronc@cse.unsw.edu.au> based | |
d60e92d1 AC |
903 | on documentation by Jens Axboe. |
904 | .SH "REPORTING BUGS" | |
482900c9 | 905 | Report bugs to the \fBfio\fR mailing list <fio@vger.kernel.org>. |
d1429b5c | 906 | See \fBREADME\fR. |
d60e92d1 | 907 | .SH "SEE ALSO" |
d1429b5c AC |
908 | For further documentation see \fBHOWTO\fR and \fBREADME\fR. |
909 | .br | |
910 | Sample jobfiles are available in the \fBexamples\fR directory. | |
d60e92d1 | 911 |