.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.
\fIupper\fR may contain a suffix as described above. If an option allows two
sets of ranges, they are separated with a `,' or `/' character. For example:
`8\-8k/8M\-4G'.
+.TP
+.I float_list
+List of floating numbers: A list of floating numbers, separated by
+a ':' charcater.
.SS "Parameter List"
.TP
.BI name \fR=\fPstr
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
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'.
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
\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
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
.TP
.BI gid \fR=\fPint
Set group ID, see \fBuid\fR.
+.TP
+.BI clat_percentiles \fR=\fPbool
+Enable the reporting of percentiles of completion latencies.
+.TP
+.BI percentile_list \fR=\fPfloat_list
+Overwrite the default list of percentiles for completion
+latencies. Each number is a floating number in the range (0,100], and
+the maximum length of the list is 20. Use ':' to separate the
+numbers. For example, --percentile_list=99.5:99.9 will cause fio to
+report the values of completion latency below which 99.5% and 99.9% of
+the observed latencies fell, respectively.
.SH OUTPUT
While running, \fBfio\fR will display the status of the created jobs. For
example:
.RE
.RE
.P
-Error Info (dependant on continue_on_error, default off):
+Error Info (dependent on continue_on_error, default off):
.RS
.B total # errors, first error code
.RE
projects / fio.git / blobdiff