explicit size is specified by \fBfilesize\fR.
.RS
.P
-Each colon in the wanted path must be escaped with a '\\'
+Each colon in the wanted path must be escaped with a '\e'
character. For instance, if the path is `/dev/dsk/foo@3,0:c' then you
would use `filename=/dev/dsk/foo@3,0\\:c' and if the path is
`F:\\filename' then you would use `filename=F\\:\\filename'.
.BI max_open_zones \fR=\fPint
When running a random write test across an entire drive many more zones will be
open than in a typical application workload. Hence this command line option
-that allows to limit the number of open zones. The number of open zones is
+that allows one to limit the number of open zones. The number of open zones is
defined as the number of zones to which write commands are issued by all
threads/processes.
.TP
supplied as a value between 0 and 100.
.P
The second, optional float is allowed for \fBpareto\fR, \fBzipf\fR and \fBnormal\fR
-distributions. It allows to set base of distribution in non-default place, giving
+distributions. It allows one to set base of distribution in non-default place, giving
more control over most probable outcome. This value is in range [0-1] which maps linearly to
range of possible random values.
Defaults are: random for \fBpareto\fR and \fBzipf\fR, and 0.5 for \fBnormal\fR.
.TP
.BI size \fR=\fPint[%|z]
The total size of file I/O for each thread of this job. Fio will run until
-this many bytes has been transferred, unless runtime is limited by other options
-(such as \fBruntime\fR, for instance, or increased/decreased by \fBio_size\fR).
+this many bytes has been transferred, unless runtime is altered by other means
+such as (1) \fBruntime\fR, (2) \fBio_size\fR, (3) \fBnumber_ios\fR, (4)
+gaps/holes while doing I/O's such as `rw=read:16K', or (5) sequential I/O
+reaching end of the file which is possible when \fBpercentage_random\fR is
+less than 100.
Fio will divide this size between the available files determined by options
such as \fBnrfiles\fR, \fBfilename\fR, unless \fBfilesize\fR is
specified by the job. If the result of division happens to be 0, the size is
flexibility to access GNU/Linux Kernel NVMe driver via libaio, IOCTLs, io_uring,
the SPDK NVMe driver, or your own custom NVMe driver. The xnvme engine includes
engine specific options. (See \fIhttps://xnvme.io/\fR).
+.TP
+.B libblkio
+Use the libblkio library (\fIhttps://gitlab.com/libblkio/libblkio\fR). The
+specific driver to use must be set using \fBlibblkio_driver\fR. If
+\fBmem\fR/\fBiomem\fR is not specified, memory allocation is delegated to
+libblkio (and so is guaranteed to work with the selected driver).
.SS "I/O engine specific parameters"
In addition, there are some parameters which are only valid when a specific
\fBioengine\fR is in use. These are used identically to normal parameters,
Normally fio will submit IO by issuing a system call to notify the kernel of
available items in the SQ ring. If this option is set, the act of submitting IO
will be done by a polling thread in the kernel. This frees up cycles for fio, at
-the cost of using more CPU in the system.
+the cost of using more CPU in the system. As submission is just the time it
+takes to fill in the sqe entries and any syscall required to wake up the idle
+kernel thread, fio will not report submission latencies.
.TP
.BI (io_uring,io_uring_cmd)sqthread_poll_cpu \fR=\fPint
When `sqthread_poll` is set, this option provides a way to define which CPU
.TP
.BI (xnvme)xnvme_iovec
If this option is set, xnvme will use vectored read/write commands.
+.TP
+.BI (libblkio)libblkio_driver \fR=\fPstr
+The libblkio driver to use. Different drivers access devices through different
+underlying interfaces. Available drivers depend on the libblkio version in use
+and are listed at \fIhttps://libblkio.gitlab.io/libblkio/blkio.html#drivers\fR
+.TP
+.BI (libblkio)libblkio_pre_connect_props \fR=\fPstr
+A colon-separated list of libblkio properties to be set after creating but
+before connecting the libblkio instance. Each property must have the format
+\fB<name>=<value>\fR. Colons can be escaped as \fB\\:\fR. These are set after
+the engine sets any other properties, so those can be overriden. Available
+properties depend on the libblkio version in use and are listed at
+\fIhttps://libblkio.gitlab.io/libblkio/blkio.html#properties\fR
+.TP
+.BI (libblkio)libblkio_pre_start_props \fR=\fPstr
+A colon-separated list of libblkio properties to be set after connecting but
+before starting the libblkio instance. Each property must have the format
+\fB<name>=<value>\fR. Colons can be escaped as \fB\\:\fR. These are set after
+the engine sets any other properties, so those can be overriden. Available
+properties depend on the libblkio version in use and are listed at
+\fIhttps://libblkio.gitlab.io/libblkio/blkio.html#properties\fR
+.TP
+.BI (libblkio)hipri
+Use poll queues. This is incompatible with \fBlibblkio_wait_mode=eventfd\fR and
+\fBlibblkio_force_enable_completion_eventfd\fR.
+.TP
+.BI (libblkio)libblkio_vectored
+Submit vectored read and write requests.
+.TP
+.BI (libblkio)libblkio_write_zeroes_on_trim
+Submit trims as "write zeroes" requests instead of discard requests.
+.TP
+.BI (libblkio)libblkio_wait_mode \fR=\fPstr
+How to wait for completions:
+.RS
+.RS
+.TP
+.B block \fR(default)
+Use a blocking call to \fBblkioq_do_io()\fR.
+.TP
+.B eventfd
+Use a blocking call to \fBread()\fR on the completion eventfd.
+.TP
+.B loop
+Use a busy loop with a non-blocking call to \fBblkioq_do_io()\fR.
+.RE
+.RE
+.TP
+.BI (libblkio)libblkio_force_enable_completion_eventfd
+Enable the queue's completion eventfd even when unused. This may impact
+performance. The default is to enable it only if
+\fBlibblkio_wait_mode=eventfd\fR.
.SS "I/O depth"
.TP
.BI iodepth \fR=\fPint
Trim this number of I/O blocks.
.TP
.BI experimental_verify \fR=\fPbool
-Enable experimental verification.
+Enable experimental verification. Standard verify records I/O metadata for
+later use during the verification phase. Experimental verify instead resets the
+file after the write phase and then replays I/Os for the verification phase.
.SS "Steady state"
.TP
.BI steadystate \fR=\fPstr:float "\fR,\fP ss" \fR=\fPstr:float
.TP
.B Trace file format v2
The second version of the trace file format was added in fio version 1.17. It
-allows to access more then one file per trace and has a bigger set of possible
+allows one to access more than one file per trace and has a bigger set of possible
file actions.
.RS
.P
projects / fio.git / blobdiff