Turn on safety read-only checks, preventing any attempted write.
.TP
.BI \-\-section \fR=\fPsec
-Only run section \fIsec\fR from job file. Multiple of these options can be given, adding more sections to run.
+Only run section \fIsec\fR from job file. This option can be used multiple times to add more sections to run.
.TP
.BI \-\-alloc\-size \fR=\fPkb
Set the internal smalloc pool size to \fIkb\fP kilobytes.
device, \\.\PhysicalDrive1 for the second etc. Note: Windows and FreeBSD
prevent write access to areas of the disk containing in-use data
(e.g. filesystems). 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".
+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".
.TP
.BI filename_format \fR=\fPstr
If sharing multiple files between jobs, it is usually necessary to have
No locking. This is the default.
.TP
.B exclusive
-Only one thread or process may do IO at the time, excluding all others.
+Only one thread or process may do IO at a time, excluding all others.
.TP
.B readwrite
Read-write locking on the file. Many readers may access the file at the same
.BI unified_rw_reporting \fR=\fPbool
Fio normally reports statistics on a per data direction basis, meaning that
read, write, and trim are accounted and reported separately. If this option is
-set, the fio will sum the results and report them as "mixed" instead.
+set fio sums the results and reports them as "mixed" instead.
.TP
.BI randrepeat \fR=\fPbool
Seed the random number generator used for random I/O patterns in a predictable
sequence depends on the \fBrandrepeat\fR setting.
.TP
.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).
+Fio can either use the random generator supplied by the OS to generate random
+offsets, or it can use its own internal generator (based on Tausworthe).
Default is to use the internal generator, which is often of better quality and
faster. Default: false.
.TP
.RE
.TP
.BI fadvise_hint \fR=\fPbool
-Use of \fBposix_fadvise\fR\|(2) to advise the kernel what I/O patterns
+Use \fBposix_fadvise\fR\|(2) to advise the kernel what I/O patterns
are likely to be issued. Default: true.
.TP
.BI size \fR=\fPint
blocksize setting.
.TP
.B zero_buffers
-Initialise buffers with all zeros. Default: fill buffers with random data.
+Initialize buffers with all zeros. Default: fill buffers with random data.
The resulting IO buffers will not be completely zeroed, unless
\fPscramble_buffers\fR is also turned off.
.TP
size, fio can alternate random and zeroed data throughout the IO buffer.
.TP
.BI buffer_pattern \fR=\fPstr
-If set, fio will fill the io buffers with this pattern. If not set, the contents
-of io buffers is defined by the other options related to buffer contents. The
+If set, fio will fill the IO buffers with this pattern. If not set, the contents
+of IO buffers is defined by the other options related to buffer contents. The
setting can be any pattern of bytes, and can be prefixed with 0x for hex
values.
.TP
Choose a file at random.
.TP
.B roundrobin
-Round robin over open files (default).
+Round robin over opened files (default).
.TP
.B sequential
Do each file in the set sequentially.
.RE
.P
-The number of I/Os to issue before switching a new file can be specified by
+The number of I/Os to issue before switching to a new file can be specified by
appending `:\fIint\fR' to the service type.
.RE
.TP
IO engine supporting direct access to Ceph Rados Block Devices (RBD) via librbd
without the need to use the kernel rbd driver. This ioengine defines engine specific
options.
+.TP
+.B gfapi
+Using Glusterfs libgfapi sync interface to direct access to Glusterfs volumes without
+having to go through FUSE. This ioengine defines engine specific
+options.
+.TP
+.B gfapi_async
+Using Glusterfs libgfapi async interface to direct access to Glusterfs volumes without
+having to go through FUSE. This ioengine defines engine specific
+options.
.RE
.P
.RE
.BI iodepth \fR=\fPint
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
+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 \fBdirect\fR=1, since buffered IO is
not async on that OS. Keep an eye on the IO depth distribution in the
.TP
.BI offset_increment \fR=\fPint
If this is provided, then the real offset becomes the
-offset + offset_increment * thread_number, where the thread number is a counter
-that starts at 0 and is incremented for each job. This option is useful if
-there are several jobs which are intended to operate on a file in parallel in
-disjoint segments, with even spacing between the starting points.
+offset + offset_increment * thread_number, where the thread number is a
+counter that starts at 0 and is incremented for each sub-job (i.e. when
+numjobs option is specified). This option is useful if there are several jobs
+which are intended to operate on a file in parallel disjoint segments, with
+even spacing between the starting points.
.TP
.BI number_ios \fR=\fPint
Fio will normally perform IOs until it has exhausted the size of the region
store data of the bandwidth of the jobs in their lifetime. The included
fio_generate_plots script uses gnuplot to turn these text files into nice
graphs. See \fBwrite_lat_log\fR for behaviour of given filename. For this
-option, the postfix is _bw.log.
+option, the postfix is _bw.x.log, where x is the index of the job (1..N,
+where N is the number of jobs)
.TP
.BI write_lat_log \fR=\fPstr
Same as \fBwrite_bw_log\fR, but writes I/O completion latencies. 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.
+filename is given with this option, the default filename of
+"jobname_type.x.log" is used, where x is the index of the job (1..N, where
+N is the number of jobs). Even if the filename is given, fio will still
+append the type of log.
.TP
.BI write_iops_log \fR=\fPstr
Same as \fBwrite_bw_log\fR, but writes IOPS. 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.
+option, the default filename of "jobname_type.x.log" is used, where x is the
+index of the job (1..N, where N is the number of jobs). Even if the filename
+is given, fio will still append the type of log.
.TP
.BI log_avg_msec \fR=\fPint
By default, fio will log an entry in the iops, latency, or bw log for every
over the specified period of time, reducing the resolution of the log.
Defaults to 0.
.TP
+.BI log_offset \fR=\fPbool
+If this is set, the iolog options will include the byte offset for the IO
+entry as well as the other data values.
+.TP
+.BI log_compression \fR=\fPint
+If this is set, fio will compress the IO logs as it goes, to keep the memory
+footprint lower. When a log reaches the specified size, that chunk is removed
+and compressed in the background. Given that IO logs are fairly highly
+compressible, this yields a nice memory savings for longer runs. The downside
+is that the compression will consume some background CPU cycles, so it may
+impact the run. This, however, is also true if the logging ends up consuming
+most of the system memory. So pick your poison. The IO logs are saved
+normally at the end of a run, by decompressing the chunks and storing them
+in the specified log file. This feature depends on the availability of zlib.
+.TP
+.BI log_store_compressed \fR=\fPbool
+If set, and \fBlog\fR_compression is also set, fio will store the log files in
+a compressed format. They can be decompressed with fio, using the
+\fB\-\-inflate-log\fR command line parameter. The files will be stored with a
+\fB\.fz\fR suffix.
+.TP
.BI disable_lat \fR=\fPbool
Disable measurements of total latency numbers. Useful only for cutting
back the number of calls to \fBgettimeofday\fR\|(2), as that does impact performance at
.SS "Ioengine Parameters List"
Some parameters are only valid when a specific ioengine is in use. These are
used identically to normal parameters, with the caveat that when used on the
-command line, the must come after the ioengine that defines them is selected.
+command line, they must come after the ioengine.
.TP
.BI (cpu)cpuload \fR=\fPint
Attempt to use the specified percentage of CPU cycles.
.TP
.BI (net, pingpong) \fR=\fPbool
Normally a network writer will just continue writing data, and a network reader
-will just consume packages. If pingpong=1 is set, a writer will send its normal
+will just consume packets. If pingpong=1 is set, a writer will send its normal
payload to the reader, then wait for the reader to send the same payload back.
This allows fio to measure network latencies. The submission and completion
latencies then measure local time spent sending or receiving, and the
projects / fio.git / blobdiff