Limit run time to \fIruntime\fR seconds.
.TP
.B \-\-bandwidth\-log
-Generate per-job bandwidth logs.
+Generate aggregate bandwidth logs.
.TP
.B \-\-minimal
Print statistics in a terse, semicolon-delimited format.
Sequential writes.
.TP
.B trim
-Sequential trim (Linux block devices only).
+Sequential trims (Linux block devices only).
.TP
.B randread
Random reads.
Random writes.
.TP
.B randtrim
-Random trim (Linux block devices only).
+Random trims (Linux block devices only).
.TP
.B rw, readwrite
Mixed sequential reads and writes.
Mixed random reads and writes.
.TP
.B trimwrite
-Trim and write mixed workload. Blocks will be trimmed first, then the same
-blocks will be written to.
+Sequential trim and write mixed workload. Blocks will be trimmed first, then
+the same blocks will be written to.
.RE
.P
+Fio defaults to read if the option is not specified.
For mixed I/O, the default split is 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 done by
.TP
.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
+reads, writes, and trims are accounted and reported separately. If this option is
set fio sums the results and reports them as "mixed" instead.
.TP
.BI randrepeat \fR=\fPbool
because ZFS doesn't support it. Default: 'posix'.
.RE
.TP
-.BI fadvise_hint \fR=\fPbool
+.BI fadvise_hint \fR=\fPstr
Use \fBposix_fadvise\fR\|(2) to advise the kernel what I/O patterns
-are likely to be issued. Default: true.
+are likely to be issued. Accepted values are:
+.RS
+.RS
+.TP
+.B 0
+Backwards compatible hint for "no hint".
+.TP
+.B 1
+Backwards compatible hint for "advise with fio workload type". This
+uses \fBFADV_RANDOM\fR for a random workload, and \fBFADV_SEQUENTIAL\fR
+for a sequential workload.
+.TP
+.B sequential
+Advise using \fBFADV_SEQUENTIAL\fR
+.TP
+.B random
+Advise using \fBFADV_RANDOM\fR
+.RE
+.RE
.TP
.BI fadvise_stream \fR=\fPint
Use \fBposix_fadvise\fR\|(2) to advise the kernel what stream ID the
.TP
.B psync
Basic \fBpread\fR\|(2) or \fBpwrite\fR\|(2) I/O.
+Default on all supported operating systems except for Windows.
.TP
.B vsync
Basic \fBreadv\fR\|(2) or \fBwritev\fR\|(2) I/O. Will emulate queuing by
Solaris native asynchronous I/O.
.TP
.B windowsaio
-Windows native asynchronous I/O.
+Windows native asynchronous I/O. Default on Windows.
.TP
.B mmap
File is memory mapped with \fBmmap\fR\|(2) and data copied using
.TP
.B cpuio
Doesn't transfer any data, but burns CPU cycles according to \fBcpuload\fR and
-\fBcpucycles\fR parameters.
+\fBcpuchunks\fR parameters. A job never finishes unless there is at least one
+non-cpuio job.
.TP
.B guasi
The GUASI I/O engine is the Generic Userspace Asynchronous Syscall Interface
Read, write and erase an MTD character device (e.g., /dev/mtd0). Discards are
treated as erases. Depending on the underlying device type, the I/O may have
to go in a certain pattern, e.g., on NAND, writing sequentially to erase blocks
-and discarding before overwriting. The writetrim mode works well for this
+and discarding before overwriting. The trimwrite mode works well for this
constraint.
.TP
.B pmemblk
Read and write through the NVML libpmemblk interface.
+.TP
+.B dev-dax
+Read and write through a DAX device exposed from persistent memory.
.RE
.P
.RE
\fBiodepth_batch_complete_max\fR=<iodepth>
.RE
-which means that we will retrieve at leat 1 IO and up to the
+which means that we will retrieve at least 1 IO and up to the
whole submitted queue depth. If none of IO has been completed
yet, we will wait.
that the \fBramp_time\fR is considered lead in time for a job, thus it will
increase the total runtime if a special timeout or runtime is specified.
.TP
+.BI steadystate \fR=\fPstr:float "\fR,\fP ss" \fR=\fPstr:float
+Define the criterion and limit for assessing steady state performance. The
+first parameter designates the criterion whereas the second parameter sets the
+threshold. When the criterion falls below the threshold for the specified
+duration, the job will stop. For example, iops_slope:0.1% will direct fio
+to terminate the job when the least squares regression slope falls below 0.1%
+of the mean IOPS. If group_reporting is enabled this will apply to all jobs in
+the group. All assessments are carried out using only data from the rolling
+collection window. Threshold limits can be expressed as a fixed value or as a
+percentage of the mean in the collection window. Below are the available steady
+state assessment criteria.
+.RS
+.RS
+.TP
+.B iops
+Collect IOPS data. Stop the job if all individual IOPS measurements are within
+the specified limit of the mean IOPS (e.g., iops:2 means that all individual
+IOPS values must be within 2 of the mean, whereas iops:0.2% means that all
+individual IOPS values must be within 0.2% of the mean IOPS to terminate the
+job).
+.TP
+.B iops_slope
+Collect IOPS data and calculate the least squares regression slope. Stop the
+job if the slope falls below the specified limit.
+.TP
+.B bw
+Collect bandwidth data. Stop the job if all individual bandwidth measurements
+are within the specified limit of the mean bandwidth.
+.TP
+.B bw_slope
+Collect bandwidth data and calculate the least squares regression slope. Stop
+the job if the slope falls below the specified limit.
+.RE
+.RE
+.TP
+.BI steadystate_duration \fR=\fPtime "\fR,\fP ss_dur" \fR=\fPtime
+A rolling window of this duration will be used to judge whether steady state
+has been reached. Data will be collected once per second. The default is 0
+which disables steady state detection.
+.TP
+.BI steadystate_ramp_time \fR=\fPtime "\fR,\fP ss_ramp" \fR=\fPtime
+Allow the job to run for the specified duration before beginning data collection
+for checking the steady state job termination criterion. The default is 0.
+.TP
.BI invalidate \fR=\fPbool
Invalidate buffer-cache for the file prior to starting I/O. Default: true.
.TP
.RS
.TP
.B malloc
-Allocate memory with \fBmalloc\fR\|(3).
+Allocate memory with \fBmalloc\fR\|(3). Default memory type.
.TP
.B shm
Use shared memory buffers allocated through \fBshmget\fR\|(2).
.BI unlink \fR=\fPbool
Unlink job files when done. Default: false.
.TP
+.BI unlink_each_loop \fR=\fPbool
+Unlink job files after each iteration or loop. Default: false.
+.TP
.BI loops \fR=\fPint
Specifies the number of iterations (runs of the same workload) of this job.
Default: 1.
decimal or a hex number). The verify_pattern if larger than a 32-bit quantity
has to be a hex number that starts with either "0x" or "0X". Use with
\fBverify\fP=str. Also, verify_pattern supports %o format, which means that for
-each block offset will be written and then verifyied back, e.g.:
+each block offset will be written and then verified back, e.g.:
.RS
.RS
\fBverify_pattern\fR=%o
not set, jobs with identical names will share the log filename. Default: true.
.TP
.BI 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
-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.x.log, where x is the index of the job (1..N,
-where N is the number of jobs). If \fBper_job_logs\fR is false, then the
-filename will not include the job index. See the \fBLOG FILE FORMATS\fR
+If given, write a bandwidth log for this job. Can be used to 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.x.log,
+where x is the index of the job (1..N, where N is the number of jobs). If
+\fBper_job_logs\fR is false, then the filename will not include the job index.
+See the \fBLOG FILE FORMATS\fR
section.
.TP
.BI write_lat_log \fR=\fPstr
append the type of log. If \fBper_job_logs\fR is false, then the filename will
not include the job index. See the \fBLOG FILE FORMATS\fR section.
.TP
+.BI write_hist_log \fR=\fPstr
+Same as \fBwrite_lat_log\fR, but writes I/O completion latency histograms. If
+no filename is given with this option, the default filename of
+"jobname_clat_hist.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. If \fBper_job_logs\fR is false, then the filename will not
+include the job index. See the \fBLOG FILE FORMATS\fR section.
+.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.x.log" is used, where x is the
instead want to log the maximum value, set this option to 1. Defaults to
0, meaning that averaged values are logged.
.TP
+.BI log_hist_msec \fR=\fPint
+Same as \fBlog_avg_msec\fR, but logs entries for completion latency histograms.
+Computing latency percentiles from averages of intervals using \fBlog_avg_msec\fR
+is innacurate. Setting this option makes fio log histogram entries over the
+specified period of time, reducing log sizes for high IOPS devices while
+retaining percentile accuracy. See \fBlog_hist_coarseness\fR as well. Defaults
+to 0, meaning histogram logging is disabled.
+.TP
+.BI log_hist_coarseness \fR=\fPint
+Integer ranging from 0 to 6, defining the coarseness of the resolution of the
+histogram logs enabled with \fBlog_hist_msec\fR. For each increment in
+coarseness, fio outputs half as many bins. Defaults to 0, for which histogram
+logs contain 1216 latency bins. See the \fBLOG FILE FORMATS\fR section.
+.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.
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 log_unix_epoch \fR=\fPbool
+If set, fio will log Unix timestamps to the log files produced by enabling
+\fBwrite_type_log\fR for each log type, instead of the default zero-based
+timestamps.
+.TP
.BI block_error_percentiles \fR=\fPbool
If set, record errors in trim block-sized units from writes and trims and output
a histogram of how many trims it took to get to errors, and what kind of error
used identically to normal parameters, with the caveat that when used on the
command line, they must come after the ioengine.
.TP
-.BI (cpu)cpuload \fR=\fPint
+.BI (cpuio)cpuload \fR=\fPint
Attempt to use the specified percentage of CPU cycles.
.TP
-.BI (cpu)cpuchunks \fR=\fPint
+.BI (cpuio)cpuchunks \fR=\fPint
Split the load into cycles of the given time. In microseconds.
.TP
-.BI (cpu)exit_on_io_done \fR=\fPbool
+.BI (cpuio)exit_on_io_done \fR=\fPbool
Detect when IO threads are done, then exit.
.TP
.BI (libaio)userspace_reap
The \fIoffset\fR is the offset, in bytes, from the start of the file, for that
particular IO. The logging of the offset can be toggled with \fBlog_offset\fR.
-If windowed logging is enabled though \fBlog_avg_msec\fR, then fio doesn't log
+If windowed logging is enabled through \fBlog_avg_msec\fR, then fio doesn't log
individual IOs. Instead of logs the average values over the specified
period of time. Since \fIdata direction\fR and \fIoffset\fR are per-IO values,
they aren't applicable if windowed logging is enabled. If windowed logging
is enabled and \fBlog_max_value\fR is set, then fio logs maximum values in
that window instead of averages.
+For histogram logging the logs look like this:
+
+.B time (msec), data direction, block-size, bin 0, bin 1, ..., bin 1215
+
+Where 'bin i' gives the frequency of IO requests with a latency falling in
+the i-th bin. See \fBlog_hist_coarseness\fR for logging fewer bins.
+
.RE
.SH CLIENT / SERVER
projects / fio.git / blobdiff