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
.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.
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.
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