.BI \-\-cmdhelp \fR=\fPcommand
Print help information for \fIcommand\fR. May be `all' for all commands.
.TP
+.BI \-\-enghelp \fR=\fPioengine[,command]
+List all commands defined by \fIioengine\fR, or print help for \fIcommand\fR defined by \fIioengine\fR.
+.TP
.BI \-\-showcmd \fR=\fPjobfile
Convert \fIjobfile\fR to a set of command-line options.
.TP
.B fio
normally makes up a file name based on the job name, thread number, and file
number. If you want to share files between threads in a job or several jobs,
-specify a \fIfilename\fR for each of them to override the default. If the I/O
-engine used is `net', \fIfilename\fR is the host and port to connect to in the
-format \fIhost\fR/\fIport\fR. If the I/O engine is file-based, you can specify
+specify a \fIfilename\fR for each of them to override the default.
+If the I/O engine is file-based, you can specify
a number of files by separating the names with a `:' character. `\-' is a
reserved name, meaning stdin or stdout, depending on the read/write direction
set.
.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
coalescing adjacents IOs into a single submission.
.TP
.B libaio
-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).
+Linux native asynchronous I/O. This ioengine defines engine specific options.
.TP
.B posixaio
POSIX asynchronous I/O using \fIaio_read\fR\|(3) and \fIaio_write\fR\|(3).
itself and for debugging and testing purposes.
.TP
.B net
-Transfer over the network. \fBfilename\fR must be set appropriately to
-`\fIhost\fR,\fIport\fR,\fItype\fR' regardless of data direction. \fItype\fR
-is one of \fBtcp\fR, \fBudp\fR, or \fBunix\fR. For UNIX domain sockets,
-the \fIhost\fR parameter is a file system path.
+Transfer over the network. The protocol to be used can be defined with the
+\fBprotocol\fR parameter. Depending on the protocol, \fBfilename\fR,
+\fBhostname\fR, \fBport\fR, or \fBlisten\fR must be specified.
+This ioengine defines engine specific options.
.TP
.B netsplice
Like \fBnet\fR, but uses \fIsplice\fR\|(2) and \fIvmsplice\fR\|(2) to map data
-and send/receive.
+and send/receive. This ioengine defines engine specific options.
.TP
.B cpuio
Doesn't transfer any data, but burns CPU cycles according to \fBcpuload\fR and
.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.
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
numbers. For example, \-\-percentile_list=99.5:99.9 will cause fio to
report the values of completion latency below which 99.5% and 99.9% of
the observed latencies fell, respectively.
+.SS "Ioengine Parameters List"
+Some parameters are only valid when a specific ioengine is in use. These are
+used identically to normal parameters, with the caveat that when used on the
+command line, the must come after the ioengine that defines them is selected.
+.TP
+.BI (libaio)userspace_reap
+Normally, with the libaio engine in use, fio will use
+the io_getevents 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 0 events (eg when
+iodepth_batch_complete=0).
+.TP
+.BI (net,netsplice)hostname \fR=\fPstr
+The host name or IP address to use for TCP or UDP based IO.
+If the job is a TCP listener or UDP reader, the hostname is not
+used and must be omitted.
+.TP
+.BI (net,netsplice)port \fR=\fPint
+The TCP or UDP port to bind to or connect to.
+.TP
+.BI (net,netsplice)protocol \fR=\fPstr "\fR,\fP proto" \fR=\fPstr
+The network protocol to use. Accepted values are:
+.RS
+.RS
+.TP
+.B tcp
+Transmission control protocol
+.TP
+.B udp
+Unreliable datagram protocol
+.TP
+.B unix
+UNIX domain socket
+.RE
+.P
+When the protocol is TCP or UDP, the port must also be given,
+as well as the hostname if the job is a TCP listener or UDP
+reader. For unix sockets, the normal filename option should be
+used and the port is invalid.
+.RE
+.TP
+.BI (net,netsplice)listen
+For TCP network connections, tell fio to listen for incoming
+connections rather than initiating an outgoing connection. The
+hostname must be omitted if this option is used.
.SH OUTPUT
While running, \fBfio\fR will display the status of the created jobs. For
example:
projects / fio.git / blobdiff