| 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://brick.kernel.dk/data/git/fio.git |
| |
| 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, you |
| can find them here: |
| |
| http://linux01.gwdg.de/~pbleser/rpm-navigation.php?cat=System/fio |
| |
| |
| Mailing list |
| ------------ |
| |
| There's a mailing list associated with fio. It's meant for general |
| discussion, bug reporting, questions - 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-devel@kernel.dk, |
| subscribe by sending an empty email to fio-devel+subscribe@kernel.dk. |
| |
| |
| Building |
| -------- |
| |
| Just type 'make' and 'make install'. If on FreeBSD, for now you have to |
| specify the FreeBSD Makefile with -f, eg: |
| |
| $ make -f Makefile.Freebsd && make -f Makefile.FreeBSD install |
| |
| Likewise with OpenSolaris, use the Makefile.solaris to compile there. |
| This might change in the future if I opt for an autoconf type setup. |
| |
| |
| Command line |
| ------------ |
| |
| $ fio |
| --output Write output to file |
| --runtime 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 |
| |
| 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. |
| |
| |
| Job file |
| -------- |
| |
| See the HOWTO file for a more detailed description of parameters and what |
| they mean. This file contains the terse version. Only a few options can |
| be controlled with command line parameters, 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 it's 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, sync for regular read/write io, |
| mmap for mmap'ed io, syslet-rw for syslet driven |
| read/write, splice for using splice/vmsplice, |
| sgio for direct SG_IO io, or net for network io. sgio |
| 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. |
| 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. |
| 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. |
| |
| |
| 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 |
| |
