| fio |
| --- |
| |
| fio is a tool that will spawn a number of threads or processes doing a |
| particular type of io action as specified by the user. fio takes a |
| number of global parameters, each inherited by the thread unless |
| otherwise parameters given to them overriding that setting is given. |
| The typical use of fio is to write a job file matching the io load |
| one wants to simulate. |
| |
| |
| Source |
| ------ |
| |
| fio resides in a git repo, the canonical place is: |
| |
| git://git.kernel.dk/fio.git |
| |
| The http protocol also works, path is the same. |
| |
| Snapshots are frequently generated and they include the git meta data as |
| well. You can download them here: |
| |
| http://brick.kernel.dk/snaps/ |
| |
| Pascal Bleser <guru@unixtech.be> has fio RPMs in his repository for |
| SUSE variants, you can find them here: |
| |
| http://linux01.gwdg.de/~pbleser/rpm-navigation.php?cat=System/fio |
| |
| Dag Wieƫrs has RPMs for Red Hat related distros, find them here: |
| |
| http://dag.wieers.com/rpm/packages/fio/ |
| |
| Mandriva has integrated fio into their package repository, so installing |
| on that distro should be as easy as typing 'urpmi fio'. |
| |
| |
| Mailing list |
| ------------ |
| |
| There's a mailing list associated with fio. It's meant for general |
| discussion, bug reporting, questions, and development - basically anything |
| that has to do with fio. An automated mail detailing recent commits is |
| automatically sent to the list at most daily. The list address is |
| fio@vger.kernel.org, subscribe by sending an email to |
| majordomo@vger.kernel.org with |
| |
| subscribe fio |
| |
| in the body of the email. There is no archive for the new list yet, |
| archives for the old list can be found here: |
| |
| http://maillist.kernel.dk/fio-devel/ |
| |
| |
| Building |
| -------- |
| |
| Just type 'make' and 'make install'. If on FreeBSD, for now you have to |
| specify the FreeBSD Makefile with -f and use gmake (not make), eg: |
| |
| $ gmake -f Makefile.Freebsd && gmake -f Makefile.FreeBSD install |
| |
| Likewise with OpenSolaris, use the Makefile.solaris to compile there. |
| The OpenSolaris make should work fine. This might change in the |
| future if I opt for an autoconf type setup. |
| |
| If your compile fails with an error like this: |
| |
| CC gettime.o |
| In file included from fio.h:23, |
| from gettime.c:8: |
| os/os.h:15:20: error: libaio.h: No such file or directory |
| In file included from gettime.c:8: |
| fio.h:119: error: field 'iocb' has incomplete type |
| make: *** [gettime.o] Error 1 |
| |
| Check that you have the libaio development package installed. On RPM |
| based distros, it's typically called libaio-devel. |
| |
| |
| Command line |
| ------------ |
| |
| $ fio |
| --debug Enable some debugging options (see below) |
| --output Write output to file |
| --timeout Runtime in seconds |
| --latency-log Generate per-job latency logs |
| --bandwidth-log Generate per-job bandwidth logs |
| --minimal Minimal (terse) output |
| --version Print version info and exit |
| --help Print this page |
| --cmdhelp=cmd Print command help, "all" for all of them |
| --showcmd Turn a job file into command line options |
| --readonly Turn on safety read-only checks, preventing writes |
| --eta=when When ETA estimate should be printed |
| May be "always", "never" or "auto" |
| --section=name Only run specified section in job file |
| --alloc-size=kb Set smalloc pool to this size in kb (def 1024) |
| |
| |
| Any parameters following the options will be assumed to be job files, |
| unless they match a job file parameter. You can add as many as you want, |
| each job file will be regarded as a separate group and fio will stonewall |
| its execution. |
| |
| The --readonly switch is an extra safety guard to prevent accidentically |
| turning on a write setting when that is not desired. Fio will only write |
| if rw=write/randwrite/rw/randrw is given, but this extra safety net can |
| be used as an extra precaution. It will also enable a write check in the |
| io engine core to prevent an accidental write due to a fio bug. |
| |
| The debug switch allows adding options that trigger certain logging |
| options in fio. Currently the options are: |
| |
| process Dump info related to processes |
| file Dump info related to file actions |
| io Dump info related to IO queuing |
| mem Dump info related to memory allocations |
| blktrace Dump info related to blktrace setup |
| verify Dump info related to IO verification |
| all Enable all debug options |
| random Dump info related to random offset generation |
| parse Dump info related to option matching and parsing |
| diskutil Dump info related to disk utilization updates |
| job:x Dump info only related to job number x |
| mutex Dump info only related to mutex up/down ops |
| ? or help Show available debug options. |
| |
| You can specify as many as you want, eg --debug=file,mem will enable |
| file and memory debugging. |
| |
| The section switch is meant to make it easier to ship a bigger job file |
| instead of several smaller ones. Say you define a job file with light, |
| moderate, and heavy parts. Then you can ask fio to run the given part |
| only by giving it a --section=heavy command line option. The section |
| option only applies to job sections, the reserved 'global' section is |
| always parsed and taken into account. |
| |
| Fio has an internal allocator for shared memory called smalloc. It |
| allocates shared structures from this pool. The pool defaults to 1024k |
| in size, and can grow to 32 pools. If running large jobs with randommap |
| enabled it can run out of memory, in which case the --alloc-size switch |
| is handy for starting with a larger pool size. |
| |
| |
| Job file |
| -------- |
| |
| See the HOWTO file for a more detailed description of parameters and what |
| they mean. This file contains the terse version. You can describe big and |
| complex setups with the command line, but generally it's a lot easier to |
| just write a simple job file to describe the workload. The job file format |
| is in the ini style format, as that is easy to read and write for the user. |
| |
| The job file parameters are: |
| |
| name=x Use 'x' as the identifier for this job. |
| description=x 'x' is a text description of the job. |
| directory=x Use 'x' as the top level directory for storing files |
| filename=x Force the use of 'x' as the filename for all files |
| in this thread. If not given, fio will make up |
| a suitable filename based on the thread and file |
| number. |
| rw=x 'x' may be: read, randread, write, randwrite, |
| rw (read-write mix), randrw (read-write random mix) |
| rwmixcycle=x Base cycle for switching between read and write |
| in msecs. |
| rwmixread=x 'x' percentage of rw mix ios will be reads. If |
| rwmixwrite is also given, the last of the two will |
| be used if they don't add up to 100%. |
| rwmixwrite=x 'x' percentage of rw mix ios will be writes. See |
| rwmixread. |
| rand_repeatable=x The sequence of random io blocks can be repeatable |
| across runs, if 'x' is 1. |
| size=x Set file size to x bytes (x string can include k/m/g) |
| ioengine=x 'x' may be: aio/libaio/linuxaio for Linux aio, |
| posixaio for POSIX aio, solarisaio for Solaris |
| native async IO, sync for regular read/write io, |
| psync for regular pread/pwrite io, vsync for regular |
| readv/writev (with queuing emulation) mmap for mmap'ed |
| io, syslet-rw for syslet driven read/write, splice for |
| using splice/vmsplice, sg for direct SG_IO io, net |
| for network io, or cpuio for a cycler burner load. sg |
| only works on Linux on SCSI (or SCSI-like devices, such |
| as usb-storage or sata/libata driven) devices. Fio also |
| has a null io engine, which is mainly used for testing |
| fio itself. |
| |
| iodepth=x For async io, allow 'x' ios in flight |
| overwrite=x If 'x', layout a write file first. |
| nrfiles=x Spread io load over 'x' number of files per job, |
| if possible. |
| prio=x Run io at prio X, 0-7 is the kernel allowed range |
| prioclass=x Run io at prio class X |
| bs=x Use 'x' for thread blocksize. May include k/m postfix. |
| bsrange=x-y Mix thread block sizes randomly between x and y. May |
| also include k/m postfix. |
| direct=x 1 for direct IO, 0 for buffered IO |
| thinktime=x "Think" x usec after each io |
| rate=x Throttle rate to x KiB/sec |
| ratemin=x Quit if rate of x KiB/sec can't be met |
| ratecycle=x ratemin averaged over x msecs |
| cpumask=x Only allow job to run on CPUs defined by mask. |
| cpus_allowed=x Like 'cpumask', but allow text setting of CPU affinity. |
| fsync=x If writing with buffered IO, fsync after every |
| 'x' blocks have been written. |
| end_fsync=x If 'x', run fsync() after end-of-job. |
| startdelay=x Start this thread x seconds after startup |
| runtime=x Terminate x seconds after startup. Can include a |
| normal time suffix if not given in seconds, such as |
| 'm' for minutes, 'h' for hours, and 'd' for days. |
| offset=x Start io at offset x (x string can include k/m/g) |
| invalidate=x Invalidate page cache for file prior to doing io |
| sync=x Use sync writes if x and writing buffered IO. |
| mem=x If x == malloc, use malloc for buffers. If x == shm, |
| use shared memory for buffers. If x == mmap, use |
| anonymous mmap. |
| exitall When one thread quits, terminate the others |
| bwavgtime=x Average bandwidth stats over an x msec window. |
| create_serialize=x If 'x', serialize file creation. |
| create_fsync=x If 'x', run fsync() after file creation. |
| unlink If set, unlink files when done. |
| loops=x Run the job 'x' number of times. |
| verify=x If 'x' == md5, use md5 for verifies. If 'x' == crc32, |
| use crc32 for verifies. md5 is 'safer', but crc32 is |
| a lot faster. Only makes sense for writing to a file. |
| For other types of checksumming, see HOWTO. |
| stonewall Wait for preceeding jobs to end before running. |
| numjobs=x Create 'x' similar entries for this job |
| thread Use pthreads instead of forked jobs |
| zonesize=x |
| zoneskip=y Zone options must be paired. If given, the job |
| will skip y bytes for every x read/written. This |
| can be used to gauge hard drive speed over the entire |
| platter, without reading everything. Both x/y can |
| include k/m/g suffix. |
| iolog=x Open and read io pattern from file 'x'. The file must |
| contain one io action per line in the following format: |
| rw, offset, length |
| where with rw=0/1 for read/write, and the offset |
| and length entries being in bytes. |
| write_iolog=x Write an iolog to file 'x' in the same format as iolog. |
| The iolog options are exclusive, if both given the |
| read iolog will be performed. |
| write_bw_log Write a bandwidth log. |
| write_lat_log Write a latency log. |
| lockmem=x Lock down x amount of memory on the machine, to |
| simulate a machine with less memory available. x can |
| include k/m/g suffix. |
| nice=x Run job at given nice value. |
| exec_prerun=x Run 'x' before job io is begun. |
| exec_postrun=x Run 'x' after job io has finished. |
| ioscheduler=x Use ioscheduler 'x' for this job. |
| cpuload=x For a CPU io thread, percentage of CPU time to attempt |
| to burn. |
| cpuchunks=x Split burn cycles into pieces of x usecs. |
| |
| |
| |
| Platforms |
| --------- |
| |
| Fio works on (at least) Linux, Solaris, and FreeBSD. Some features and/or |
| options may only be available on some of the platforms, typically because |
| those features only apply to that platform (like the solarisaio engine, or |
| the splice engine on Linux). |
| |
| Some features are not available on FreeBSD/Solaris even if they could be |
| implemented, I'd be happy to take patches for that. An example of that is |
| disk utility statistics and (I think) huge page support, support for that |
| does exist in FreeBSD/Solaris. |
| |
| Fio uses pthread mutexes for signalling and locking and FreeBSD does not |
| support process shared pthread mutexes. As a result, only threads are |
| supported on FreeBSD. This could be fixed with sysv ipc locking or |
| other locking alternatives. |
| |
| Other *BSD platforms are untested, but fio should work there almost out |
| of the box. Since I don't do test runs or even compiles on those platforms, |
| your mileage may vary. Sending me patches for other platforms is greatly |
| appreciated. There's a lot of value in having the same test/benchmark tool |
| available on all platforms. |
| |
| |
| |
| Author |
| ------ |
| |
| Fio was written by Jens Axboe <axboe@kernel.dk> to enable flexible testing |
| of the Linux IO subsystem and schedulers. He got tired of writing |
| specific test applications to simulate a given workload, and found that |
| the existing io benchmark/test tools out there weren't flexible enough |
| to do what he wanted. |
| |
| Jens Axboe <axboe@kernel.dk> 20060905 |
| |