.BI \-\-output \fR=\fPfilename
Write output to \fIfilename\fR.
.TP
-.BI \-\-timeout \fR=\fPtimeout
-Limit run time to \fItimeout\fR seconds.
+.BI \-\-runtime \fR=\fPruntime
+Limit run time to \fIruntime\fR seconds.
.TP
.B \-\-latency\-log
Generate per-job latency logs.
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
.RE
.TP
.BI fadvise_hint \fR=\fPbool
-Disable use of \fIposix_fadvise\fR\|(2) to advise the kernel what I/O patterns
+Use of \fIposix_fadvise\fR\|(2) to advise the kernel what I/O patterns
are likely to be issued. Default: true.
.TP
.BI size \fR=\fPint
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
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
+.BI log_avg_msec \fR=\fPint
+By default, fio will log an entry in the iops, latency, or bw log for every
+IO that completes. When writing to the disk log, that can quickly grow to a
+very large size. Setting this option makes fio average the each log entry
+over the specified period of time, reducing the resolution of the log.
+Defaults to 0.
+.TP
.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
.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
on that machine, where args defines what fio listens to. The arguments
are of the form 'type:hostname or IP:port'. 'type' is either 'ip' (or ip4)
-for TCP/IP v4, 'ip6' for TCP/IP v6, or 'sock' for a local unix domain socket.
-'hostname' is either a hostname or IP address, and 'port' is the port to
+for TCP/IP v4, 'ip6' for TCP/IP v6, or 'sock' for a local unix domain
+socket. 'hostname' is either a hostname or IP address, and 'port' is the port to
listen to (only valid for TCP/IP, not a local socket). Some examples:
-1) fio --server
+1) fio \-\-server
Start a fio server, listening on all interfaces on the default port (8765).
-2) fio --server=ip:hostname,4444
+2) fio \-\-server=ip:hostname,4444
Start a fio server, listening on IP belonging to hostname and on port 4444.
-3) fio --server=ip6:::1,4444
+3) fio \-\-server=ip6:::1,4444
Start a fio server, listening on IPv6 localhost ::1 and on port 4444.
-4) fio --server=,4444
+4) fio \-\-server=,4444
Start a fio server, listening on all interfaces on port 4444.
-5) fio --server=1.2.3.4
+5) fio \-\-server=1.2.3.4
Start a fio server, listening on IP 1.2.3.4 on the default port.
-6) fio --server=sock:/tmp/fio.sock
+6) fio \-\-server=sock:/tmp/fio.sock
Start a fio server, listening on the local socket /tmp/fio.sock.
When a server is running, you can connect to it from a client. The client
is run with:
-fio --local-args --client=server --remote-args <job file(s)>
+fio \-\-local-args \-\-client=server \-\-remote-args <job file(s)>
-where --local-args are arguments that are local to the client where it is
-running, 'server' is the connect string, and --remote-args and <job file(s)>
+where \-\-local-args are arguments that are local to the client where it is
+running, 'server' is the connect string, and \-\-remote-args and <job file(s)>
are sent to the server. The 'server' string follows the same format as it
does on the server side, to allow IP/hostname/socket and port strings.
You can connect to multiple clients as well, to do that you could run:
-fio --client=server2 --client=server2 <job file(s)>
+fio \-\-client=server2 \-\-client=server2 <job file(s)>
.SH AUTHORS
.B fio
projects / fio.git / blobdiff