defined by \fIioengine\fR. If no \fIioengine\fR is given, list all
available ioengines.
.TP
-.BI \-\-showcmd \fR=\fPjobfile
-Convert \fIjobfile\fR to a set of command\-line options.
+.BI \-\-showcmd
+Convert given \fIjobfile\fRs to a set of command\-line options.
.TP
.BI \-\-readonly
Turn on safety read\-only checks, preventing writes and trims. The \fB\-\-readonly\fR
.RS
.P
.PD 0
-z means Zone
+z means Zone
.P
.PD
.RE
.TP
.B trimwrite
Sequential trim+write sequences. Blocks will be trimmed first,
-then the same blocks will be written to.
+then the same blocks will be written to. So if `io_size=64K' is specified,
+Fio will trim a total of 64K bytes and also write 64K bytes on the same
+trimmed blocks. This behaviour will be consistent with `number_ios' or
+other Fio options limiting the total bytes or number of I/O's.
+.TP
+.B randtrimwrite
+Like
+.B trimwrite ,
+but uses random offsets rather than sequential writes.
.RE
.P
Fio defaults to read if the option is not specified. For the mixed I/O
effectively caps the file size at `real_size \- offset'. Can be combined with
\fBsize\fR to constrain the start and end range of the I/O workload.
A percentage can be specified by a number between 1 and 100 followed by '%',
-for example, `offset=20%' to specify 20%. In ZBD mode, value can be set as
+for example, `offset=20%' to specify 20%. In ZBD mode, value can be set as
number of zones using 'z'.
.TP
.BI offset_align \fR=\fPint
intended to operate on a file in parallel disjoint segments, with even
spacing between the starting points. Percentages can be used for this option.
If a percentage is given, the generated offset will be aligned to the minimum
-\fBblocksize\fR or to the value of \fBoffset_align\fR if provided.In ZBD mode, value
+\fBblocksize\fR or to the value of \fBoffset_align\fR if provided.In ZBD mode, value
can be set as number of zones using 'z'.
.TP
.BI number_ios \fR=\fPint
files or devices. If the files do not exist, size must be given. It is also
possible to give size as a percentage between 1 and 100. If `size=20%' is
given, fio will use 20% of the full size of the given files or devices. In ZBD mode,
-size can be given in units of number of zones using 'z'. Can be combined with \fBoffset\fR to
+size can be given in units of number of zones using 'z'. Can be combined with \fBoffset\fR to
constrain the start and end range that I/O will be done within.
.TP
.BI io_size \fR=\fPint[%|z] "\fR,\fB io_limit" \fR=\fPint[%|z]
.BI filesize \fR=\fPirange(int)
Individual file sizes. May be a range, in which case fio will select sizes
for files at random within the given range. If not given, each created file
-is the same size. This option overrides \fBsize\fR in terms of file size,
+is the same size. This option overrides \fBsize\fR in terms of file size,
i.e. \fBsize\fR becomes merely the default for \fBio_size\fR (and
has no effect it all if \fBio_size\fR is set explicitly).
.TP
Specify the label or UUID of the DAOS container to open.
.TP
.BI (dfs)chunk_size
-Specificy a different chunk size (in bytes) for the dfs file.
+Specify a different chunk size (in bytes) for the dfs file.
Use DAOS container's chunk size by default.
.TP
.BI (dfs)object_class
-Specificy a different object class for the dfs file.
+Specify a different object class for the dfs file.
Use DAOS container's object class by default.
.TP
.BI (nfs)nfs_url
completed. If this option is used, there are two more stats that are
appended, the total error count and the first error. The error field given
in the stats is the first error that was hit during the run.
+.RS
+.P
+Note: a write error from the device may go unnoticed by fio when using buffered
+IO, as the write() (or similar) system call merely dirties the kernel pages,
+unless `sync' or `direct' is used. Device IO errors occur when the dirty data is
+actually written out to disk. If fully sync writes aren't desirable, `fsync' or
+`fdatasync' can be used as well. This is specific to writes, as reads are always
+synchronous.
+.RS
+.P
The allowed values are:
.RS
.RS
projects / fio.git / blobdiff