.TP
.B \-\-version
Display version information and exit.
+.TP
+.B \-\-terse\-version\fR=\fPtype
+Terse version output format
.SH "JOB FILE FORMAT"
Job files are in `ini' format. They consist of one or more
job definitions, which begin with a job name in square brackets and
specify a number of IO's to do before getting a new offset, this is one by
appending a `:\fI<nr>\fR to the end of the string given. For a random read, it
would look like \fBrw=randread:8\fR for passing in an offset modifier with a
-value of 8. See the \fBrw_sequencer\fR option.
+value of 8. If the postfix is used with a sequential IO pattern, then the value
+specified will be added to the generated offset for each IO. For instance,
+using \fBrw=write:4k\fR will skip 4k for every write. It turns sequential IO
+into sequential IO with holes. See the \fBrw_sequencer\fR option.
.RE
.TP
.BI rw_sequencer \fR=\fPstr
if zero_buffers isn't specified, naturally. If data verification is enabled,
refill_buffers is also automatically enabled.
.TP
+.BI scramble_buffers \fR=\fPbool
+If \fBrefill_buffers\fR is too costly and the target is using data
+deduplication, then setting this option will slightly modify the IO buffer
+contents to defeat normal de-dupe attempts. This is not enough to defeat
+more clever block compression attempts, but it will stop naive dedupe
+of blocks. Default: true.
+.TP
.BI nrfiles \fR=\fPint
Number of files to use for this job. Default: 1.
.TP
coalescing adjacents IOs into a single submission.
.TP
.B libaio
-Linux native asynchronous I/O.
+Linux native asynchronous I/O. This engine also has a sub-option,
+\fBuserspace_reap\fR. To set it, use \fBioengine=libaio:userspace_reap\fR.
+Normally, with the libaio engine in use, fio will use the
+\fIio_getevents\fR\|(3) system call to reap newly returned events. With this
+flag turned on, the AIO ring will be read directly from user-space to reap
+events. The reaping mode is only enabled when polling for a minimum of \fB0\fR
+events (eg when \fBiodepth_batch_complete=0\fR).
.TP
.B posixaio
POSIX asynchronous I/O using \fIaio_read\fR\|(3) and \fIaio_write\fR\|(3).
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
+.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_log_log\fR for behaviour of given filename. For this
option, the postfix is _bw.log.
.TP
-.B write_lat_log \fR=\fPstr
+.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.
.TP
-.B disable_lat \fR=\fPbool
+.BI disable_lat \fR=\fPbool
Disable measurements of total latency numbers. Useful only for cutting
back the number of calls to gettimeofday, as that does impact performance at
really high IOPS rates. Note that to really get rid of a large amount of these
calls, this option must be used with disable_slat and disable_bw as well.
.TP
-.B disable_clat \fR=\fPbool
+.BI disable_clat \fR=\fPbool
Disable measurements of completion latency numbers. See \fBdisable_lat\fR.
.TP
-.B disable_slat \fR=\fPbool
+.BI disable_slat \fR=\fPbool
Disable measurements of submission latency numbers. See \fBdisable_lat\fR.
.TP
-.B disable_bw_measurement \fR=\fPbool
+.BI disable_bw_measurement \fR=\fPbool
Disable measurements of throughput/bandwidth numbers. See \fBdisable_lat\fR.
.TP
.BI lockmem \fR=\fPint
.P
Read status:
.RS
-.B KB I/O, bandwidth \fR(KB/s)\fP, runtime \fR(ms)\fP
+.B Total I/O \fR(KB)\fP, bandwidth \fR(KB/s)\fP, runtime \fR(ms)\fP
.P
Submission latency:
.RS
.P
Write status:
.RS
-.B KB I/O, bandwidth \fR(KB/s)\fP, runtime \fR(ms)\fP
+.B Total I/O \fR(KB)\fP, bandwidth \fR(KB/s)\fP, runtime \fR(ms)\fP
.P
Submission latency:
.RS
projects / fio.git / blobdiff