.TP
.BI \-\-debug \fR=\fPtype
Enable verbose tracing of various fio actions. May be `all' for all types
-or individual types seperated by a comma (eg \-\-debug=io,file). `help' will
+or individual types separated by a comma (eg \-\-debug=io,file). `help' will
list all available tracing options.
.TP
.B \-\-help
of the value. Accepted suffixes are `k', 'M', 'G', 'T', and 'P', denoting
kilo (1024), mega (1024^2), giga (1024^3), tera (1024^4), and peta (1024^5)
respectively. The suffix is not case sensitive. If prefixed with '0x', the
-value is assumed to be base 16 (hexadecimal). A suffix may include a trailing
-'b', for instance 'kb' is identical to 'k'. You can specify a base 10 value
+value is assumed to be base 16 (hexadecimal). A suffix may include a trailing 'b',
+for instance 'kb' is identical to 'k'. You can specify a base 10 value
by using 'KiB', 'MiB', 'GiB', etc. This is useful for disk drives where
values are often given in base 10 values. Specifying '30GiB' will get you
30*1000^3 bytes.
Seed the random number generator in a predictable way so results are repeatable
across runs. Default: true.
.TP
-.BI fallocate \fR=\fPbool
-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.
+.BI use_os_rand \fR=\fPbool
+Fio can either use the random generator supplied by the OS to generator random
+offsets, or it can use it's own internal generator (based on Tausworthe).
+Default is to use the internal generator, which is often of better quality and
+faster. Default: false.
+.TP
+.BI fallocate \fR=\fPstr
+Whether pre-allocation is performed when laying down files. Accepted values
+are:
+.RS
+.RS
+.TP
+.B none
+Do not pre-allocate space.
+.TP
+.B posix
+Pre-allocate via posix_fallocate().
+.TP
+.B keep
+Pre-allocate via fallocate() with FALLOC_FL_KEEP_SIZE set.
+.TP
+.B 0
+Backward-compatible alias for 'none'.
+.TP
+.B 1
+Backward-compatible alias for 'posix'.
+.RE
+.P
+May not be available on all supported platforms. 'keep' is only
+available on Linux. If using ZFS on Solaris this must be set to 'none'
+because ZFS doesn't support it. Default: 'posix'.
+.RE
.TP
.BI fadvise_hint \fR=\fPbool
Disable use of \fIposix_fadvise\fR\|(2) to advise the kernel what I/O patterns
.BI size \fR=\fPint
Total size of I/O for this job. \fBfio\fR will run until this many bytes have
been transfered, unless limited by other options (\fBruntime\fR, for instance).
-Unless \fBnr_files\fR and \fBfilesize\fR options are given, this amount will be
+Unless \fBnrfiles\fR and \fBfilesize\fR options are given, this amount will be
divided between the available files for 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.
+must be given. It is also possible to give size as a percentage between 1 and
+100. If size=20% is given, fio will use 20% of the full size of the given files
+or devices.
.TP
-.BI fill_device \fR=\fPbool
+.BI fill_device \fR=\fPbool "\fR,\fB fill_fs" \fR=\fPbool
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.
+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.
.TP
.BI filesize \fR=\fPirange
Individual file sizes. May be a range, in which case \fBfio\fR will select sizes
not just even splits between them. With this option, you can weight various
block sizes for exact control of the issued IO for a job that has mixed
block sizes. The format of the option is bssplit=blocksize/percentage,
-optionally adding as many definitions as needed seperated by a colon.
+optionally adding as many definitions as needed separated by a colon.
Example: bssplit=4k/10:64k/50:32k/40 would issue 50% 64k blocks, 10% 4k
blocks and 40% 32k blocks. \fBbssplit\fR also supports giving separate
splits to reads and writes. The format is identical to what the
Linux native asynchronous I/O.
.TP
.B posixaio
-glibc POSIX asynchronous I/O using \fIaio_read\fR\|(3) and \fIaio_write\fR\|(3).
+POSIX asynchronous I/O using \fIaio_read\fR\|(3) and \fIaio_write\fR\|(3).
+.TP
+.B solarisaio
+Solaris native asynchronous I/O.
+.TP
+.B windowsaio
+Windows native asynchronous I/O.
.TP
.B mmap
File is memory mapped with \fImmap\fR\|(2) and data copied using
.br
See <http://www.xmailserver.org/guasi\-lib.html>.
.TP
+.B rdma
+The RDMA I/O engine supports both RDMA memory semantics (RDMA_WRITE/RDMA_READ)
+and channel semantics (Send/Recv) for the InfiniBand, RoCE and iWARP protocols.
+.TP
.B external
Loads an external I/O engine object file. Append the engine filename as
`:\fIenginepath\fR'.
.RE
.TP
.BI iodepth \fR=\fPint
-Number of I/O units to keep in flight against the file. Default: 1.
+Number of I/O units to keep in flight against the file. Note that increasing
+iodepth beyond 1 will not affect synchronous ioengines (except for small
+degress when verify_async is in use). Even async engines my impose OS
+restrictions causing the desired depth not to be achieved. This may happen on
+Linux when using libaio and not setting \fBdirect\fR=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.
.TP
.BI iodepth_batch \fR=\fPint
Number of I/Os to submit at once. Default: \fBiodepth\fR.
this parameter is given, a new offset will be chosen without looking at past
I/O history. This parameter is mutually exclusive with \fBverify\fR.
.TP
-.B softrandommap
+.BI softrandommap \fR=\fPbool
See \fBnorandommap\fR. If fio runs with the random block map enabled and it
fails to allocate the map, if this option is set it will continue without a
random block map. As coverage will not be as complete as with random maps, this
use.
.RE
.TP
-.BI iomem_align \fR=\fPint
+.BI iomem_align \fR=\fPint "\fR,\fP mem_align" \fR=\fPint
This indiciates the memory alignment of the IO memory buffers. Note that the
given alignment is applied to the first IO unit buffer, if using \fBiodepth\fR
the alignment of the following buffers are given by the \fBbs\fR used. In
If true, exit the job on the first observed verification failure. Default:
false.
.TP
+.BI verify_dump \fR=\fPbool
+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.
+.TP
.BI verify_async \fR=\fPint
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
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.
+be used up holding this meta data. If this option is enabled, fio will write
+only N blocks before verifying these blocks.
.TP
.BI verify_backlog_batch \fR=\fPint
Control how many blocks fio will verify if verify_backlog is set. If not set,
will default to the value of \fBverify_backlog\fR (meaning the entire queue is
-read back and verified).
+read back and verified). If \fBverify_backlog_batch\fR is less than
+\fBverify_backlog\fR then not all blocks will be verified, if
+\fBverify_backlog_batch\fR is larger than \fBverify_backlog\fR, some blocks
+will be verified more than once.
.TP
-.B stonewall
-Wait for preceeding jobs in the job file to exit before starting this one.
+.B stonewall "\fR,\fP wait_for_previous"
+Wait for preceding jobs in the job file to exit before starting this one.
\fBstonewall\fR implies \fBnew_group\fR.
.TP
.B new_group
read.
.TP
.BI write_iolog \fR=\fPstr
-Write the issued I/O patterns to the specified file.
+Write the issued I/O patterns to the specified file. Specify a separate file
+for each job, otherwise the iologs will be interspersed and the file may be
+corrupt.
.TP
.BI read_iolog \fR=\fPstr
Replay the I/O patterns contained in the specified file generated by
\fBreplay_no_stall\fR causes I/Os to be replayed as fast as possible while
still respecting ordering.
.TP
+.BI replay_redirect \fR=\fPstr
+While replaying I/O patterns using \fBread_iolog\fR the default behavior
+is to replay the IOPS onto the major/minor device that each IOP was recorded
+from. Setting \fBreplay_redirect\fR causes all IOPS to be replayed onto the
+single specified device regardless of the device it was recorded from.
+.TP
.B write_bw_log \fR=\fPstr
If given, write a bandwidth log of the jobs in this job file. Can be used to
store data of the bandwidth of the jobs in their lifetime. The included
calls, this option must be used with disable_slat and disable_bw as well.
.TP
.B disable_clat \fR=\fPbool
-Disable measurements of submission latency numbers. See \fBdisable_lat\fR.
+Disable measurements of completion latency numbers. See \fBdisable_lat\fR.
.TP
.B disable_slat \fR=\fPbool
Disable measurements of submission latency numbers. See \fBdisable_lat\fR.
The system must have a mounted cgroup blkio mount point for this to work. If
your system doesn't have it mounted, you can do so with:
-# mount -t cgroup -o blkio none /cgroup
+# mount \-t cgroup \-o blkio none /cgroup
.TP
.BI cgroup_weight \fR=\fPint
Set the weight of the cgroup to this value. See the documentation that comes
.PD
.SH TERSE OUTPUT
If the \fB\-\-minimal\fR option is given, the results will be printed in a
-semicolon-delimited format suitable for scripted use. Note that the first
+semicolon-delimited format suitable for scripted use - a job description
+(if provided) follows on a new line. Note that the first
number in the line is the version number. If the output has to be changed
for some reason, this number will be incremented by 1 to signify that
change. The fields are:
.B <=1, 2, 4, 8, 16, 32, >=64
.RE
.P
-IO latency distribution (ms):
+IO latency distribution:
+.RS
+Microseconds:
+.RS
+.B <=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000
+.RE
+Milliseconds:
+.RS
+.B <=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000, 2000, >=2000
+.RE
+.RE
+.P
+Error Info (dependent on continue_on_error, default off):
.RS
-.B <=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000, >=2000
+.B total # errors, first error code
.RE
.P
-.B text description
+.B text description (if provided in config - appears on newline)
.RE
.SH AUTHORS
.B fio
projects / fio.git / blobdiff