int SI integer. A whole number value, which may contain a suffix
describing the base of the number. Accepted suffixes are k/m/g/t/p,
meaning kilo, mega, giga, tera, and peta. The suffix is not case
- sensitive. So if you want to specify 4096, you could either write
+ sensitive, and you may also include trailing 'b' (eg 'kb' is the same
+ as 'k'). So if you want to specify 4096, you could either write
out '4096' or just give 4k. The suffixes signify base 2 values, so
- 1024 is 1k and 1024k is 1m and so on. If the option accepts an upper
- and lower range, use a colon ':' or minus '-' to separate such values.
- May also include a prefix to indicate numbers base. If 0x is used,
- the number is assumed to be hexadecimal. See irange.
+ 1024 is 1k and 1024k is 1m and so on, unless the suffix is explicitly
+ set to a base 10 value using 'kib', 'mib', 'gib', etc. If that is the
+ case, then 1000 is used as the multiplier. This can be handy for
+ disks, since manufacturers generally use base 10 values when listing
+ the capacity of a drive. If the option accepts an upper and lower
+ range, use a colon ':' or minus '-' to separate such values. May also
+ include a prefix to indicate numbers base. If 0x is used, the number
+ is assumed to be hexadecimal. See irange.
bool Boolean. Usually parsed as an integer, however only defined for
true and false (1 and 0).
irange Integer range with suffix. Allows value range to be given, such
For the mixed io types, the default is to split them 50/50.
For certain types of io the result may still be skewed a bit,
since the speed may be different. It is possible to specify
- a number of IO's to do before getting a new offset - this
- is only useful for random IO, where fio would normally
- generate a new random offset for every IO. If you append
- eg 8 to randread, you would get a new random offset for
+ a number of IO's to do before getting a new offset, this is
+ one by appending a ':<nr>' to the end of the string given.
+ For a random read, it would look like 'rw=randread:8' for
+ passing in an offset modifier with a value of 8. See the
+ 'rw_sequencer' option.
+
+rw_sequencer=str If an offset modifier is given by appending a number to
+ the rw=<str> line, then this option controls how that
+ number modifies the IO offset being generated. Accepted
+ values are:
+
+ sequential Generate sequential offset
+ identical Generate the same offset
+
+ 'sequential' is only useful for random IO, where fio would
+ normally generate a new random offset for every IO. If you
+ append eg 8 to randread, you would get a new random offset for
every 8 IO's. The result would be a seek for only every 8
IO's, instead of for every IO. Use rw=randread:8 to specify
- that.
+ that. As sequential IO is already sequential, setting
+ 'sequential' for that would not result in any differences.
+ 'identical' behaves in a similar fashion, except it sends
+ the same offset 8 number of times before generating a new
+ offset.
kb_base=int The base unit for a kilobyte. The defacto base is 2^10, 1024.
Storage manufacturers like to use 10^3 or 1000 as a base
limited by other options (such as 'runtime', for instance).
Unless specific nrfiles and filesize options are given,
fio will divide this size between the available files
- specified by the job.
+ specified by the job. If not set, fio will use the full
+ size of the given files or devices. If the the files
+ do not exist, size must be given.
filesize=int Individual file sizes. May be a range, in which case fio
will select sizes for files at random within the given range
it in the header of each block.
crc32c-intel Use hardware assisted crc32c calcuation
- provided on SSE4.2 enabled processors.
+ provided on SSE4.2 enabled processors. Falls
+ back to regular software crc32c, if not
+ supported by the system.
crc32 Use a crc32 sum of the data area and store
it in the header of each block.
meta Write extra information about each io
(timestamp, block number etc.). The block
- number is verified.
+ number is verified. See also verify_pattern.
null Only pretend to verify. Useful for testing
internals with ioengine=null, not for much
width of the pattern, fio will fill 1/2/3/4 bytes of the
buffer at the time(it can be either a decimal or a hex number).
The verify_pattern if larger than a 32-bit quantity has to
- be a hex number that starts with either "0x" or "0X".
+ be a hex number that starts with either "0x" or "0X". Use
+ with verify=meta.
verify_fatal=bool Normally fio will keep checking the entire contents
before quitting on a block verification failure. If this
verify_async_cpus=str Tell fio to set the given CPU affinity on the
async IO verification threads. See cpus_allowed for the
format used.
+
+verify_backlog=int Fio will normally verify the written contents of a
+ job that utilizes verify once that job has completed. In
+ other words, everything is written then everything is read
+ back and verified. You may want to verify continually
+ instead for a variety of reasons. Fio stores the meta data
+ associated with an IO block in memory, so for large
+ verify workloads, quite a bit of memory would be used up
+ holding this meta data. If this option is enabled, fio
+ will verify the previously written blocks before continuing
+ to write new ones.
+
+verify_backlog_batch=int Control how many blocks fio will verify
+ if verify_backlog is set. If not set, will default to
+ the value of verify_backlog (meaning the entire queue
+ is read back and verified).
stonewall Wait for preceeding jobs in the job file to exit, before
starting this one. Can be used to insert serialization
for how to capture such logging data. For blktrace replay,
the file needs to be turned into a blkparse binary data
file first (blkparse <device> -o /dev/null -d file_for_fio.bin).
+
+replay_no_stall=int When replaying I/O with read_iolog the default behavior
+ is to attempt to respect the time stamps within the log and replay
+ them with the appropriate delay between IOPS. By setting this variable
+ fio will not respect the timestamps and attempt to replay them as fast
+ as possible while still respecting ordering. The result is the same
+ I/O pattern to a given device, but different timings.
+
+replay_redirect=str While replaying I/O patterns using read_iolog the
+ default behavior is to replay the IOPS onto the major/minor
+ device that each IOP was recorded from. This is sometimes
+ undesireable because on a different machine those major/minor
+ numbers can map to a different device. Changing hardware on
+ the same system can also result in a different major/minor
+ mapping. Replay_redirect causes all IOPS to be replayed onto
+ the single specified device regardless of the device it was
+ recorded from. i.e. replay_redirect=/dev/sdc would cause all
+ IO in the blktrace to be replayed onto /dev/sdc. This means
+ multiple devices will be replayed onto a single, if the trace
+ contains multiple devices. If you want multiple devices to be
+ replayed concurrently to multiple redirected devices you must
+ blkparse your trace into separate traces and replay them with
+ independent fio invocations. Unfortuantely this also breaks
+ the strict time ordering between multiple device accesses.
write_bw_log=str If given, write a bandwidth log of the jobs in this job
file. Can be used to store data of the bandwidth of the
filename. For this option, the postfix is _bw.log.
write_lat_log=str Same as write_bw_log, except that this option stores io
- completion latencies instead. If no filename is given
- with this option, the default filename of "jobname_type.log"
- is used. Even if the filename is given, fio will still
- append the type of log. So if one specifies
+ submission, completion, and total latencies instead. If no
+ filename is given with this option, the default filename of
+ "jobname_type.log" is used. Even if the filename is given,
+ fio will still append the type of log. So if one specifies
write_lat_log=foo
- The actual log names will be foo_clat.log and foo_slat.log.
- This helps fio_generate_plot fine the logs automatically.
+ The actual log names will be foo_slat.log, foo_slat.log,
+ and foo_lat.log. This helps fio_generate_plot fine the logs
+ automatically.
lockmem=int Pin down the specified amount of memory with mlock(2). Can
potentially be used instead of removing memory or booting
disk_util=bool Generate disk utilization statistics, if the platform
supports it. Defaults to on.
-disable_clat=bool Disable measurements of completion latency numbers. Useful
+disable_lat=bool Disable measurements of total latency numbers. Useful
only for cutting back the number of calls to gettimeofday,
as that does impact performance at really high IOPS rates.
Note that to really get rid of a large amount of these
calls, this option must be used with disable_slat and
disable_bw as well.
+disable_clat=bool Disable measurements of completion latency numbers. See
+ disable_lat.
+
disable_slat=bool Disable measurements of submission latency numbers. See
- disable_clat.
+ disable_slat.
disable_bw=bool Disable measurements of throughput/bandwidth numbers. See
- disable_clat.
+ disable_lat.
gtod_reduce=bool Enable all of the gettimeofday() reducing options
(disable_clat, disable_slat, disable_bw) plus reduce
of the results, fio can output the results in a semicolon separated format.
The format is one long line of values, such as:
-client1;0;0;1906777;1090804;1790;0;0;0.000000;0.000000;0;0;0.000000;0.000000;929380;1152890;25.510151%;1078276.333333;128948.113404;0;0;0;0;0;0.000000;0.000000;0;0;0.000000;0.000000;0;0;0.000000%;0.000000;0.000000;100.000000%;0.000000%;324;100.0%;0.0%;0.0%;0.0%;0.0%;0.0%;0.0%;100.0%;0.0%;0.0%;0.0%;0.0%;0.0%
+2; client1;0;0;1906777;1090804;1790;0;0;0.000000;0.000000;0;0;0.000000;0.000000;929380;1152890;25.510151%;1078276.333333;128948.113404;0;0;0;0;0;0.000000;0.000000;0;0;0.000000;0.000000;0;0;0.000000%;0.000000;0.000000;100.000000%;0.000000%;324;100.0%;0.0%;0.0%;0.0%;0.0%;0.0%;0.0%;100.0%;0.0%;0.0%;0.0%;0.0%;0.0%
;0.0%;0.0%;0.0%;0.0%;0.0%
-To enable terse output, use the --minimal command line option.
+To enable terse output, use the --minimal command line option. The first
+value is the version of the terse output format. If the output has to
+be changed for some reason, this number will be incremented by 1 to
+signify that change.
Split up, the format is as follows:
- jobname, groupid, error
+ version, jobname, groupid, error
READ status:
KB IO, bandwidth (KB/sec), runtime (msec)
Submission latency: min, max, mean, deviation
Completion latency: min, max, mean, deviation
+ Total latency: min, max, mean, deviation
Bw: min, max, aggregate percentage of total, mean, deviation
WRITE status:
KB IO, bandwidth (KB/sec), runtime (msec)
Submission latency: min, max, mean, deviation
Completion latency: min, max, mean, deviation
+ Total latency: min, max, mean, deviation
Bw: min, max, aggregate percentage of total, mean, deviation
CPU usage: user, system, context switches, major faults, minor faults
IO depths: <=1, 2, 4, 8, 16, 32, >=64
projects / fio.git / blobdiff