All fio parser warnings are fatal, causing fio to exit with an error.
.TP
.BI \-\-max\-jobs \fR=\fPnr
-Set the maximum allowed number of jobs (threads/processes) to suport.
+Set the maximum allowed number of jobs (threads/processes) to support.
.TP
.BI \-\-server \fR=\fPargs
Start a backend server, with \fIargs\fP specifying what to listen to. See client/server section.
.B randwrite
Random writes.
.TP
-.B rw
+.B rw, readwrite
Mixed sequential reads and writes.
.TP
.B randrw
.P
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 one by
+specify a number of IO's to do before getting a new offset, this is done 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. If the postfix is used with a sequential IO pattern, then the value
more clever block compression attempts, but it will stop naive dedupe
of blocks. Default: true.
.TP
+.BI buffer_compress_percentage \fR=\fPint
+If this is set, then fio will attempt to provide IO buffer content (on WRITEs)
+that compress to the specified level. Fio does this by providing a mix of
+random data and zeroes. Note that this is per block size unit, for file/disk
+wide compression level that matches this setting, you'll also want to set
+\fBrefill_buffers\fR.
+.TP
+.BI buffer_compress_chunk \fR=\fPint
+See \fBbuffer_compress_percentage\fR. This setting allows fio to manage how
+big the ranges of random data and zeroed data is. Without this set, fio will
+provide \fBbuffer_compress_percentage\fR of blocksize random data, followed by
+the remaining zeroed. With this set to some chunk size smaller than the block
+size, fio can alternate random and zeroed data throughout the IO buffer.
+.TP
.BI nrfiles \fR=\fPint
Number of files to use for this job. Default: 1.
.TP
.BI offset \fR=\fPint
Offset in the file to start I/O. Data before the offset will not be touched.
.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.
+.TP
.BI fsync \fR=\fPint
How many I/Os to perform before issuing an \fBfsync\fR\|(2) of dirty data. If
0, don't sync. Default: 0.
If true, sync file contents on close. This differs from \fBend_fsync\fR in that
it will happen on every close, not just at the end of the job. Default: false.
.TP
-.BI rwmixcycle \fR=\fPint
-How many milliseconds before switching between reads and writes for a mixed
-workload. Default: 500ms.
-.TP
.BI rwmixread \fR=\fPint
Percentage of a mixed workload that should be reads. Default: 50.
.TP
.BI create_on_open \fR=\fPbool
If true, the files are not created until they are opened for IO by the job.
.TP
+.BI create_only \fR=\fPbool
+If true, fio will only run the setup phase of the job. If files need to be
+laid out or updated on disk, only that will be done. The actual job contents
+are not executed.
+.TP
.BI pre_read \fR=\fPbool
If this is given, files will be pre-read into memory before starting the given
IO operation. This will also clear the \fR \fBinvalidate\fR flag, since it is
.BI gid \fR=\fPint
Set group ID, see \fBuid\fR.
.TP
+.BI flow_id \fR=\fPint
+The ID of the flow. If not specified, it defaults to being a global flow. See
+\fBflow\fR.
+.TP
+.BI flow \fR=\fPint
+Weight in token-based flow control. If this value is used, then there is a
+\fBflow counter\fR which is used to regulate the proportion of activity between
+two or more jobs. fio attempts to keep this flow counter near zero. The
+\fBflow\fR parameter stands for how much should be added or subtracted to the
+flow counter on each iteration of the main I/O loop. That is, if one job has
+\fBflow=8\fR and another job has \fBflow=-1\fR, then there will be a roughly
+1:8 ratio in how much one runs vs the other.
+.TP
+.BI flow_watermark \fR=\fPint
+The maximum value that the absolute value of the flow counter is allowed to
+reach before the job must wait for a lower value of the counter.
+.TP
+.BI flow_sleep \fR=\fPint
+The period of time, in microseconds, to wait after the flow watermark has been
+exceeded before retrying operations
+.TP
.BI clat_percentiles \fR=\fPbool
Enable the reporting of percentiles of completion latencies.
.TP
Disk utilization.
.RE
.PD
+.P
+It is also possible to get fio to dump the current output while it is
+running, without terminating the job. To do that, send fio the \fBUSR1\fR
+signal.
.SH TERSE OUTPUT
If the \fB\-\-minimal\fR option is given, the results will be printed in a
semicolon-delimited format suitable for scripted use - a job description
projects / fio.git / blobdiff