4 fio is a tool that will spawn a number of threads or processes doing a
5 particular type of io action as specified by the user. fio takes a
6 number of global parameters, each inherited by the thread unless
7 otherwise parameters given to them overriding that setting is given.
8 The typical use of fio is to write a job file matching the io load
15 fio resides in a git repo, the canonical place is:
17 git://git.kernel.dk/fio.git
19 If you are inside a corporate firewall, git:// may not always work for
20 you. In that case you can use the http protocol, path is the same:
22 http://git.kernel.dk/fio.git
24 Snapshots are frequently generated and they include the git meta data as
25 well. You can download them here:
27 http://brick.kernel.dk/snaps/
34 Starting with Debian "Squeeze", fio packages are part of the official
35 Debian repository. http://packages.debian.org/search?keywords=fio
38 Starting with Ubuntu 10.04 LTS (aka "Lucid Lynx"), fio packages are part
39 of the Ubuntu "universe" repository.
40 http://packages.ubuntu.com/search?keywords=fio
43 Pascal Bleser <guru@unixtech.be> has fio RPMs in his repository for SUSE
44 variants, you can find them here:
45 http://linux01.gwdg.de/~pbleser/rpm-navigation.php?cat=System/fio
48 Dag Wieƫrs has RPMs for Red Hat related distros, find them here:
49 http://dag.wieers.com/rpm/packages/fio/
52 Mandriva has integrated fio into their package repository, so installing
53 on that distro should be as easy as typing 'urpmi fio'.
56 Packages for Solaris are available from OpenCSW. Install their pkgutil
57 tool (http://www.opencsw.org/get-it/pkgutil/) and then install fio via
61 Bruce Cran <bruce@cran.org.uk> has fio packages for Windows at
62 http://www.bluestop.org/fio .
68 There's a mailing list associated with fio. It's meant for general
69 discussion, bug reporting, questions, and development - basically anything
70 that has to do with fio. An automated mail detailing recent commits is
71 automatically sent to the list at most daily. The list address is
72 fio@vger.kernel.org, subscribe by sending an email to
73 majordomo@vger.kernel.org with
77 in the body of the email. Archives can be found here:
79 http://www.spinics.net/lists/fio/
81 and archives for the old list can be found here:
83 http://maillist.kernel.dk/fio-devel/
89 Just type 'make' and 'make install'.
91 Note that GNU make is required. On BSD it's available from devel/gmake;
92 on Solaris it's in the SUNWgmake package. On platforms where GNU make
93 isn't the default, type 'gmake' instead of 'make'.
95 If your compile fails with an error like this:
98 In file included from fio.h:23,
100 os/os.h:15:20: error: libaio.h: No such file or directory
101 In file included from gettime.c:8:
102 fio.h:119: error: field 'iocb' has incomplete type
103 make: *** [gettime.o] Error 1
105 Check that you have the libaio development package installed. On RPM
106 based distros, it's typically called libaio-devel.
112 On Windows Cygwin (http://www.cygwin.com) is required with at least
113 devel/gcc4 and devel/make installed in order to build fio, and
114 admin/cygrunsrv to run it. You can also install devel/git to fetch/update
115 the source files. To create an MSI installer package put a copy of Cygwin
116 in os\windows\fio, install WiX 3.6 from http://wix.sourceforge.net/releases/
117 and run dobuild.cmd from the os/windows directory.
119 Before running fio you'll need to have a copy of cygserver running. Run
120 "/usr/bin/cygserver-config" from an elevated Cygwin shell (i.e. launch the
121 Cygwin shell under the Administrator account) to configure it. Once
122 configured, run "net start cygserver" to start it, or type
123 "/usr/sbin/cygserver &" in the Cygwin shell to start a local copy.
125 If fio exits with the message "Bad system call" it normally means that
126 Cygserver isn't running.
133 --debug Enable some debugging options (see below)
134 --output Write output to file
135 --timeout Runtime in seconds
136 --latency-log Generate per-job latency logs
137 --bandwidth-log Generate per-job bandwidth logs
138 --minimal Minimal (terse) output
139 --version Print version info and exit
140 --terse-version=type Terse version output format
141 --help Print this page
142 --cmdhelp=cmd Print command help, "all" for all of them
143 --showcmd Turn a job file into command line options
144 --readonly Turn on safety read-only checks, preventing
146 --eta=when When ETA estimate should be printed
147 May be "always", "never" or "auto"
148 --section=name Only run specified section in job file. Multiple
149 sections can be specified.
150 --alloc-size=kb Set smalloc pool to this size in kb (def 1024)
151 --warnings-fatal Fio parser warnings are fatal
152 --max-jobs Maximum number of threads/processes to support
155 Any parameters following the options will be assumed to be job files,
156 unless they match a job file parameter. You can add as many as you want,
157 each job file will be regarded as a separate group and fio will stonewall
160 The --readonly switch is an extra safety guard to prevent accidentally
161 turning on a write setting when that is not desired. Fio will only write
162 if rw=write/randwrite/rw/randrw is given, but this extra safety net can
163 be used as an extra precaution. It will also enable a write check in the
164 io engine core to prevent an accidental write due to a fio bug.
166 The debug switch allows adding options that trigger certain logging
167 options in fio. Currently the options are:
169 process Dump info related to processes
170 file Dump info related to file actions
171 io Dump info related to IO queuing
172 mem Dump info related to memory allocations
173 blktrace Dump info related to blktrace setup
174 verify Dump info related to IO verification
175 all Enable all debug options
176 random Dump info related to random offset generation
177 parse Dump info related to option matching and parsing
178 diskutil Dump info related to disk utilization updates
179 job:x Dump info only related to job number x
180 mutex Dump info only related to mutex up/down ops
181 profile Dump info related to profile extensions
182 time Dump info related to internal time keeping
183 ? or help Show available debug options.
185 You can specify as many as you want, eg --debug=file,mem will enable
186 file and memory debugging.
188 The section switch is meant to make it easier to ship a bigger job file
189 instead of several smaller ones. Say you define a job file with light,
190 moderate, and heavy parts. Then you can ask fio to run the given part
191 only by giving it a --section=heavy command line option. The section
192 option only applies to job sections, the reserved 'global' section is
193 always parsed and taken into account.
195 Fio has an internal allocator for shared memory called smalloc. It
196 allocates shared structures from this pool. The pool defaults to 1024k
197 in size, and can grow to 128 pools. If running large jobs with randommap
198 enabled it can run out of memory, in which case the --alloc-size switch
199 is handy for starting with a larger pool size. The backing store is
200 files in /tmp. Fio cleans up after itself, while it is running you
201 may see .fio_smalloc.* files in /tmp.
207 See the HOWTO file for a more detailed description of parameters and what
208 they mean. This file contains the terse version. You can describe big and
209 complex setups with the command line, but generally it's a lot easier to
210 just write a simple job file to describe the workload. The job file format
211 is in the ini style format, as that is easy to read and write for the user.
213 The job file parameters are:
215 name=x Use 'x' as the identifier for this job.
216 description=x 'x' is a text description of the job.
217 directory=x Use 'x' as the top level directory for storing files
218 filename=x Force the use of 'x' as the filename for all files
219 in this thread. If not given, fio will make up
220 a suitable filename based on the thread and file
222 rw=x 'x' may be: read, randread, write, randwrite,
223 rw (read-write mix), randrw (read-write random mix)
224 rwmixcycle=x Base cycle for switching between read and write
226 rwmixread=x 'x' percentage of rw mix ios will be reads. If
227 rwmixwrite is also given, the last of the two will
228 be used if they don't add up to 100%.
229 rwmixwrite=x 'x' percentage of rw mix ios will be writes. See
231 rand_repeatable=x The sequence of random io blocks can be repeatable
232 across runs, if 'x' is 1.
233 size=x Set file size to x bytes (x string can include k/m/g)
234 ioengine=x 'x' may be: aio/libaio/linuxaio for Linux aio,
235 posixaio for POSIX aio, solarisaio for Solaris
236 native async IO, windowsaio for Windows native async IO,
237 sync for regular read/write io,
238 psync for regular pread/pwrite io, vsync for regular
239 readv/writev (with queuing emulation) mmap for mmap'ed
240 io, syslet-rw for syslet driven read/write, splice for
241 using splice/vmsplice, sg for direct SG_IO io, net
242 for network io, or cpuio for a cycler burner load. sg
243 only works on Linux on SCSI (or SCSI-like devices, such
244 as usb-storage or sata/libata driven) devices. Fio also
245 has a null io engine, which is mainly used for testing
248 iodepth=x For async io, allow 'x' ios in flight
249 overwrite=x If 'x', layout a write file first.
250 nrfiles=x Spread io load over 'x' number of files per job,
252 prio=x Run io at prio X, 0-7 is the kernel allowed range
253 prioclass=x Run io at prio class X
254 bs=x Use 'x' for thread blocksize. May include k/m postfix.
255 bsrange=x-y Mix thread block sizes randomly between x and y. May
256 also include k/m postfix.
257 direct=x 1 for direct IO, 0 for buffered IO
258 thinktime=x "Think" x usec after each io
259 rate=x Throttle rate to x KB/sec
260 ratemin=x Quit if rate of x KB/sec can't be met
261 ratecycle=x ratemin averaged over x msecs
262 cpumask=x Only allow job to run on CPUs defined by mask.
263 cpus_allowed=x Like 'cpumask', but allow text setting of CPU affinity.
264 fsync=x If writing with buffered IO, fsync after every
265 'x' blocks have been written.
266 end_fsync=x If 'x', run fsync() after end-of-job.
267 startdelay=x Start this thread x seconds after startup
268 runtime=x Terminate x seconds after startup. Can include a
269 normal time suffix if not given in seconds, such as
270 'm' for minutes, 'h' for hours, and 'd' for days.
271 offset=x Start io at offset x (x string can include k/m/g)
272 invalidate=x Invalidate page cache for file prior to doing io
273 sync=x Use sync writes if x and writing buffered IO.
274 mem=x If x == malloc, use malloc for buffers. If x == shm,
275 use shared memory for buffers. If x == mmap, use
277 exitall When one thread quits, terminate the others
278 bwavgtime=x Average bandwidth stats over an x msec window.
279 create_serialize=x If 'x', serialize file creation.
280 create_fsync=x If 'x', run fsync() after file creation.
281 unlink If set, unlink files when done.
282 loops=x Run the job 'x' number of times.
283 verify=x If 'x' == md5, use md5 for verifies. If 'x' == crc32,
284 use crc32 for verifies. md5 is 'safer', but crc32 is
285 a lot faster. Only makes sense for writing to a file.
286 For other types of checksumming, see HOWTO.
287 stonewall Wait for preceeding jobs to end before running.
288 numjobs=x Create 'x' similar entries for this job
289 thread Use pthreads instead of forked jobs
291 zoneskip=y Zone options must be paired. If given, the job
292 will skip y bytes for every x read/written. This
293 can be used to gauge hard drive speed over the entire
294 platter, without reading everything. Both x/y can
295 include k/m/g suffix.
296 read_iolog=x Open and read io pattern from file 'x'. The file format
297 is described in the HOWTO.
298 write_iolog=x Write an iolog to file 'x' in the same format as iolog.
299 The iolog options are exclusive, if both given the
300 read iolog will be performed. Specify a separate file
301 for each job, otherwise the iologs will be interspersed
302 and the file may be corrupt.
303 write_bw_log Write a bandwidth log.
304 write_lat_log Write a latency log.
305 lockmem=x Lock down x amount of memory on the machine, to
306 simulate a machine with less memory available. x can
307 include k/m/g suffix.
308 nice=x Run job at given nice value.
309 exec_prerun=x Run 'x' before job io is begun.
310 exec_postrun=x Run 'x' after job io has finished.
311 ioscheduler=x Use ioscheduler 'x' for this job.
312 cpuload=x For a CPU io thread, percentage of CPU time to attempt
314 cpuchunks=x Split burn cycles into pieces of x usecs.
321 Fio works on (at least) Linux, Solaris, AIX, HP-UX, OSX, NetBSD, Windows
322 and FreeBSD. Some features and/or options may only be available on some of
323 the platforms, typically because those features only apply to that platform
324 (like the solarisaio engine, or the splice engine on Linux).
326 Some features are not available on FreeBSD/Solaris even if they could be
327 implemented, I'd be happy to take patches for that. An example of that is
328 disk utility statistics and (I think) huge page support, support for that
329 does exist in FreeBSD/Solaris.
331 Fio uses pthread mutexes for signalling and locking and FreeBSD does not
332 support process shared pthread mutexes. As a result, only threads are
333 supported on FreeBSD. This could be fixed with sysv ipc locking or
334 other locking alternatives.
336 Other *BSD platforms are untested, but fio should work there almost out
337 of the box. Since I don't do test runs or even compiles on those platforms,
338 your mileage may vary. Sending me patches for other platforms is greatly
339 appreciated. There's a lot of value in having the same test/benchmark tool
340 available on all platforms.
342 Note that POSIX aio is not enabled by default on AIX. If you get messages like:
344 Symbol resolution failed for /usr/lib/libc.a(posix_aio.o) because:
345 Symbol _posix_kaio_rdwr (number 2) is not exported from dependent module /unix.
347 you need to enable POSIX aio. Run the following commands as root:
349 # lsdev -C -l posix_aio0
350 posix_aio0 Defined Posix Asynchronous I/O
351 # cfgmgr -l posix_aio0
352 # lsdev -C -l posix_aio0
353 posix_aio0 Available Posix Asynchronous I/O
355 POSIX aio should work now. To make the change permanent:
357 # chdev -l posix_aio0 -P -a autoconfig='available'
364 Fio was written by Jens Axboe <axboe@kernel.dk> to enable flexible testing
365 of the Linux IO subsystem and schedulers. He got tired of writing
366 specific test applications to simulate a given workload, and found that
367 the existing io benchmark/test tools out there weren't flexible enough
368 to do what he wanted.
370 Jens Axboe <axboe@kernel.dk> 20060905