can specify a number of files by separating the names with a
':' colon. So if you wanted a job to open /dev/sda and /dev/sdb
as the two working files, you would use
- filename=/dev/sda:/dev/sdb. If the wanted filename does need to
- include a colon, then escape that with a '\' character. For
- instance, if the filename is "/dev/dsk/foo@3,0:c", then you would
- use filename="/dev/dsk/foo@3,0\:c". '-' is a reserved name,
- meaning stdin or stdout. Which of the two depends on the read/write
- direction set.
+ filename=/dev/sda:/dev/sdb. On Windows, disk devices are accessed
+ as \\.\PhysicalDrive0 for the first device, \\.\PhysicalDrive1
+ for the second etc. If the wanted filename does need to
+ include a colon, then escape that with a '\' character.
+ For instance, if the filename is "/dev/dsk/foo@3,0:c",
+ then you would use filename="/dev/dsk/foo@3,0\:c".
+ '-' is a reserved name, meaning stdin or stdout. Which of the
+ two depends on the read/write direction set.
opendir=str Tell fio to recursively add any file it can find in this
directory and down the file system tree.
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
fallocate=bool By default, fio will use fallocate() to advise the system
of the size of the file we are going to write. This can be
turned off with fallocate=0. May not be available on all
- supported platforms.
+ supported platforms. If using ZFS on Solaris this must be
+ set to 0 because ZFS doesn't support it.
fadvise_hint=bool By default, fio will use fadvise() to advise the kernel
on what IO patterns it is likely to issue. Sometimes you
fill_device=bool Sets size to something really large and waits for ENOSPC (no
space left on device) as the terminating condition. Only makes
sense with sequential write. For a read workload, the mount
- point will be filled first then IO started on the result.
+ point will be filled first then IO started on the result. This
+ option doesn't make sense if operating on a raw device node,
+ since the size of that is already known by the file system.
+ Additionally, writing beyond end-of-device will not return
+ ENOSPC there.
blocksize=int
bs=int The block size used for the io units. Defaults to 4k. Values
solarisaio Solaris native asynchronous io.
+ windowsaio Windows native asynchronous io.
+
mmap File is memory mapped and data copied
to/from using memcpy(3).
iodepth=int This defines how many io units to keep in flight against
the file. The default is 1 for each file defined in this
job, can be overridden with a larger value for higher
- concurrency.
+ concurrency. Note that increasing iodepth beyond 1 will not
+ affect synchronous ioengines (except for small degress when
+ verify_async is in use). Even async engines may impose OS
+ restrictions causing the desired depth not to be achieved.
+ This may happen on Linux when using libaio and not setting
+ direct=1, since buffered IO is not async on that OS. Keep an
+ eye on the IO depth distribution in the fio output to verify
+ that the achieved depth is as expected. Default: 1.
iodepth_batch_submit=int
iodepth_batch=int This defines how many pieces of IO to submit at once.
the depth drain down to 4 before starting to fill it again.
direct=bool If value is true, use non-buffered io. This is usually
- O_DIRECT.
+ O_DIRECT. Note that ZFS on Solaris doesn't support direct io.
buffered=bool If value is true, use buffered io. This is the opposite
of the 'direct' option. Defaults to true.
option is set, fio will exit the job on the first observed
failure.
+verify_dump=bool If set, dump the contents of both the original data
+ block and the data block we read off disk to files. This
+ allows later analysis to inspect just what kind of data
+ corruption occurred. On by default.
+
verify_async=int Fio will normally verify IO inline from the submitting
thread. This option takes an integer describing how many
async offload threads to create for IO verification instead,
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 write only N blocks before verifying these blocks.
+
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).
+ is read back and verified). If verify_backlog_batch is
+ less than verify_backlog then not all blocks will be verified,
+ if verify_backlog_batch is larger than verify_backlog, some
+ blocks will be verified more than once.
stonewall Wait for preceeding jobs in the job file to exit, before
starting this one. Can be used to insert serialization
io on zones of a file.
write_iolog=str Write the issued io patterns to the specified file. See
- read_iolog.
+ read_iolog. Specify a separate file for each job, otherwise
+ the iologs will be interspersed and the file may be corrupt.
read_iolog=str Open an iolog with the specified file name and replay the
io patterns it contains. This can be used to store a
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
of the results, fio can output the results in a semicolon separated format.
The format is one long line of values, such as:
-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%
+2;card0;0;0;7139336;121836;60004;1;10109;27.932460;116.933948;220;126861;3495.446807;1085.368601;226;126864;3523.635629;1089.012448;24063;99944;50.275485%;59818.274627;5540.657370;7155060;122104;60004;1;8338;29.086342;117.839068;388;128077;5032.488518;1234.785715;391;128085;5061.839412;1236.909129;23436;100928;50.287926%;59964.832030;5644.844189;14.595833%;19.394167%;123706;0;7313;0.1%;0.1%;0.1%;0.1%;0.1%;0.1%;100.0%;0.00%;0.00%;0.00%;0.00%;0.00%;0.00%;0.01%;0.02%;0.05%;0.16%;6.04%;40.40%;52.68%;0.64%;0.01%;0.00%;0.01%;0.00%;0.00%;0.00%;0.00%;0.00%
+A description of this job goes here.
+
+The job description (if provided) follows on a second line.
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
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
- IO latencies: <=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000, >=2000
- Text description
-
+ IO latencies microseconds: <=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000
+ IO latencies milliseconds: <=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000, 2000, >=2000
+ Additional Info (dependant on continue_on_error, default off): total # errors, first error code
+
+ Additional Info (dependant on description being set): Text description
projects / fio.git / blobdiff