Limit on the number of simultaneously opened zones per single thread/process.
.TP
.BI ignore_zone_limits \fR=\fPbool
-If this isn't set, fio will query the max open zones limit from the zoned block
-device, and exit if the specified \fBmax_open_zones\fR value is larger than the
-limit reported by the device. Default: false.
+If this option is used, fio will ignore the maximum number of open zones limit
+of the zoned block device in use, thus allowing the option \fBmax_open_zones\fR
+value to be larger than the device reported limit. Default: false.
.TP
.BI zone_reset_threshold \fR=\fPfloat
A number between zero and one that indicates the ratio of logical blocks with
.TP
.BI fdatasync \fR=\fPint
Like \fBfsync\fR but uses \fBfdatasync\fR\|(2) to only sync data and
-not metadata blocks. In Windows, FreeBSD, DragonFlyBSD or OSX there is no
+not metadata blocks. In Windows, DragonFlyBSD or OSX there is no
\fBfdatasync\fR\|(2) so this falls back to using \fBfsync\fR\|(2).
Defaults to 0, which means fio does not periodically issue and wait for a
data-only sync to complete.
range of possible random values.
Defaults are: random for \fBpareto\fR and \fBzipf\fR, and 0.5 for \fBnormal\fR.
If you wanted to use \fBzipf\fR with a `theta` of 1.2 centered on 1/4 of allowed value range,
-you would use `random_distibution=zipf:1.2:0.25`.
+you would use `random_distribution=zipf:1.2:0.25`.
.P
For a \fBzoned\fR distribution, fio supports specifying percentages of I/O
access that should fall within what range of the file or device. For
.TP
.BI filesize \fR=\fPirange(int)
Individual file sizes. May be a range, in which case fio will select sizes
-for files at random within the given range and limited to \fBsize\fR in
-total (if that is given). If not given, each created file is the same size.
-This option overrides \fBsize\fR in terms of file size, which means
-this value is used as a fixed size or possible range of each file.
+for files at random within the given range. If not given, each created file
+is the same size. This option overrides \fBsize\fR in terms of file size,
+i.e. \fBsize\fR becomes merely the default for \fBio_size\fR (and
+has no effect it all if \fBio_size\fR is set explicitly).
.TP
.BI file_append \fR=\fPbool
Perform I/O after the end of the file. Normally fio will operate within the
the percentage of IOs that must have a priority set depending on the block
size of the IO. This option is useful only when used together with the option
\fBbssplit\fR, that is, multiple different block sizes are used for reads and
-writes. The format for this option is the same as the format of the
-\fBbssplit\fR option, with the exception that values for trim IOs are
-ignored. This option is mutually exclusive with the \fBcmdprio_percentage\fR
-option.
+writes.
+.RS
+.P
+The first accepted format for this option is the same as the format of the
+\fBbssplit\fR option:
+.RS
+.P
+cmdprio_bssplit=blocksize/percentage:blocksize/percentage
+.RE
+.P
+In this case, each entry will use the priority class and priority level defined
+by the options \fBcmdprio_class\fR and \fBcmdprio\fR respectively.
+.P
+The second accepted format for this option is:
+.RS
+.P
+cmdprio_bssplit=blocksize/percentage/class/level:blocksize/percentage/class/level
+.RE
+.P
+In this case, the priority class and priority level is defined inside each
+entry. In comparison with the first accepted format, the second accepted format
+does not restrict all entries to have the same priority class and priority
+level.
+.P
+For both formats, only the read and write data directions are supported, values
+for trim IOs are ignored. This option is mutually exclusive with the
+\fBcmdprio_percentage\fR option.
+.RE
.TP
.BI (io_uring)fixedbufs
If fio is asked to do direct IO, then Linux will map pages for each IO call, and
.BI (cpuio)cpuchunks \fR=\fPint
Split the load into cycles of the given time. In microseconds.
.TP
+.BI (cpuio)cpumode \fR=\fPstr
+Specify how to stress the CPU. It can take these two values:
+.RS
+.RS
+.TP
+.B noop
+This is the default and directs the CPU to execute noop instructions.
+.TP
+.B qsort
+Replace the default noop instructions with a qsort algorithm to consume more energy.
+.RE
+.RE
+.TP
.BI (cpuio)exit_on_io_done \fR=\fPbool
Detect when I/O threads are done, then exit.
.TP
unit access (fua) flag. Default: 0.
.TP
.BI (sg)sg_write_mode \fR=\fPstr
-Specify the type of write commands to issue. This option can take three
+Specify the type of write commands to issue. This option can take multiple
values:
.RS
.RS
.B write (default)
Write opcodes are issued as usual
.TP
+.B write_and_verify
+Issue WRITE AND VERIFY commands. The BYTCHK bit is set to 00b. This directs the
+device to carry out a medium verification with no data comparison for the data
+that was written. The writefua option is ignored with this selection.
+.TP
.B verify
-Issue WRITE AND VERIFY commands. The BYTCHK bit is set to 0. This
-directs the device to carry out a medium verification with no data
-comparison. The writefua option is ignored with this selection.
+This option is deprecated. Use write_and_verify instead.
.TP
-.B same
+.B write_same
Issue WRITE SAME commands. This transfers a single block to the device
and writes this same block of data to a contiguous sequence of LBAs
beginning at the specified offset. fio's block size parameter
generate 8k of data for each command butonly the first 512 bytes will
be used and transferred to the device. The writefua option is ignored
with this selection.
+.TP
+.B same
+This option is deprecated. Use write_same instead.
+.TP
+.B write_same_ndob
+Issue WRITE SAME(16) commands as above but with the No Data Output
+Buffer (NDOB) bit set. No data will be transferred to the device with
+this bit set. Data written will be a pre-determined pattern such as
+all zeroes.
+.TP
+.B write_stream
+Issue WRITE STREAM(16) commands. Use the stream_id option to specify
+the stream identifier.
+.TP
+.B verify_bytchk_00
+Issue VERIFY commands with BYTCHK set to 00. This directs the device to carry
+out a medium verification with no data comparison.
+.TP
+.B verify_bytchk_01
+Issue VERIFY commands with BYTCHK set to 01. This directs the device to
+compare the data on the device with the data transferred to the device.
+.TP
+.B verify_bytchk_11
+Issue VERIFY commands with BYTCHK set to 11. This transfers a single block to
+the device and compares the contents of this block with the data on the device
+beginning at the specified offset. fio's block size parameter specifies the
+total amount of data compared with this command. However, only one block
+(sector) worth of data is transferred to the device. This is similar to the
+WRITE SAME command except that data is compared instead of written.
.RE
.RE
.TP
+.BI (sg)stream_id \fR=\fPint
+Set the stream identifier for WRITE STREAM commands. If this is set to 0 (which is not
+a valid stream identifier) fio will open a stream and then close it when done. Default
+is 0.
+.TP
.BI (nbd)uri \fR=\fPstr
Specify the NBD URI of the server to test.
The string is a standard NBD URI (see
To avoid false verification errors, do not use the norandommap option when
verifying data with async I/O engines and I/O depths > 1. Or use the
norandommap and the lfsr random generator together to avoid writing to the
-same offset with muliple outstanding I/Os.
+same offset with multiple outstanding I/Os.
.RE
.TP
.BI verify_offset \fR=\fPint
.TP
.B wait
Wait for `offset' microseconds. Everything below 100 is discarded.
-The time is relative to the previous `wait' statement.
+The time is relative to the previous `wait' statement. Note that action `wait`
+is not allowed as of version 3, as the same behavior can be achieved using
+timestamps.
.TP
.B read
Read `length' bytes beginning from `offset'.
Trim the given file from the given `offset' for `length' bytes.
.RE
.RE
+.RE
+.TP
+.B Trace file format v3
+The third version of the trace file format was added in fio version 3.31. It
+forces each action to have a timestamp associated with it.
+.RS
+.P
+The first line of the trace file has to be:
+.RS
+.P
+"fio version 3 iolog"
+.RE
+.P
+Following this can be lines in two different formats, which are described below.
+.P
+.B
+The file management format:
+.RS
+timestamp filename action
+.P
+.RE
+.B
+The file I/O action format:
+.RS
+timestamp filename action offset length
+.P
+The `timestamp` is relative to the beginning of the run (ie starts at 0). The
+`filename`, `action`, `offset` and `length` are identical to version 2, except
+that version 3 does not allow the `wait` action.
+.RE
+.RE
.SH I/O REPLAY \- MERGING TRACES
Colocation is a common practice used to get the most out of a machine.
Knowing which workloads play nicely with each other and which ones don't is
projects / fio.git / blobdiff