.TP
.BI fdatasync \fR=\fPint
Like \fBfsync\fR but uses \fBfdatasync\fR\|(2) to only sync data and
-not metadata blocks. In Windows, FreeBSD, DragonFlyBSD or OSX there is no
+not metadata blocks. In Windows, DragonFlyBSD or OSX there is no
\fBfdatasync\fR\|(2) so this falls back to using \fBfsync\fR\|(2).
Defaults to 0, which means fio does not periodically issue and wait for a
data-only sync to complete.
.TP
.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 and limited to \fBsize\fR in
-total (if that is given). If not given, each created file is the same size.
-This option overrides \fBsize\fR in terms of file size, which means
-this value is used as a fixed size or possible range of each file.
+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,
+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
.BI file_append \fR=\fPbool
Perform I/O after the end of the file. Normally fio will operate within the
the percentage of IOs that must have a priority set depending on the block
size of the IO. This option is useful only when used together with the option
\fBbssplit\fR, that is, multiple different block sizes are used for reads and
-writes. The format for this option is the same as the format of the
-\fBbssplit\fR option, with the exception that values for trim IOs are
-ignored. This option is mutually exclusive with the \fBcmdprio_percentage\fR
-option.
+writes.
+.RS
+.P
+The first accepted format for this option is the same as the format of the
+\fBbssplit\fR option:
+.RS
+.P
+cmdprio_bssplit=blocksize/percentage:blocksize/percentage
+.RE
+.P
+In this case, each entry will use the priority class and priority level defined
+by the options \fBcmdprio_class\fR and \fBcmdprio\fR respectively.
+.P
+The second accepted format for this option is:
+.RS
+.P
+cmdprio_bssplit=blocksize/percentage/class/level:blocksize/percentage/class/level
+.RE
+.P
+In this case, the priority class and priority level is defined inside each
+entry. In comparison with the first accepted format, the second accepted format
+does not restrict all entries to have the same priority class and priority
+level.
+.P
+For both formats, only the read and write data directions are supported, values
+for trim IOs are ignored. This option is mutually exclusive with the
+\fBcmdprio_percentage\fR option.
+.RE
.TP
.BI (io_uring)fixedbufs
If fio is asked to do direct IO, then Linux will map pages for each IO call, and
.B write (default)
Write opcodes are issued as usual
.TP
-.B verify
+.B write_and_verify
Issue WRITE AND VERIFY commands. The BYTCHK bit is set to 00b. This directs the
device to carry out a medium verification with no data comparison for the data
that was written. The writefua option is ignored with this selection.
.TP
-.B same
+.B verify
+This option is deprecated. Use write_and_verify instead.
+.TP
+.B write_same
Issue WRITE SAME commands. This transfers a single block to the device
and writes this same block of data to a contiguous sequence of LBAs
beginning at the specified offset. fio's block size parameter
be used and transferred to the device. The writefua option is ignored
with this selection.
.TP
+.B same
+This option is deprecated. Use write_same instead.
+.TP
.B write_same_ndob
Issue WRITE SAME(16) commands as above but with the No Data Output
Buffer (NDOB) bit set. No data will be transferred to the device with
this bit set. Data written will be a pre-determined pattern such as
all zeroes.
.TP
+.B write_stream
+Issue WRITE STREAM(16) commands. Use the stream_id option to specify
+the stream identifier.
+.TP
.B verify_bytchk_00
Issue VERIFY commands with BYTCHK set to 00. This directs the device to carry
out a medium verification with no data comparison.
.RE
.RE
.TP
+.BI (sg)stream_id \fR=\fPint
+Set the stream identifier for WRITE STREAM commands. If this is set to 0 (which is not
+a valid stream identifier) fio will open a stream and then close it when done. Default
+is 0.
+.TP
.BI (nbd)uri \fR=\fPstr
Specify the NBD URI of the server to test.
The string is a standard NBD URI (see
write_type_log for each log type, instead of the default zero-based
timestamps.
.TP
+.BI log_alternate_epoch \fR=\fPbool
+If set, fio will log timestamps based on the epoch used by the clock specified
+in the \fBlog_alternate_epoch_clock_id\fR option, to the log files produced by
+enabling write_type_log for each log type, instead of the default zero-based
+timestamps.
+.TP
+.BI log_alternate_epoch_clock_id \fR=\fPint
+Specifies the clock_id to be used by clock_gettime to obtain the alternate epoch
+if either \fBBlog_unix_epoch\fR or \fBlog_alternate_epoch\fR are true. Otherwise has no
+effect. Default value is 0, or CLOCK_REALTIME.
+.TP
.BI block_error_percentiles \fR=\fPbool
If set, record errors in trim block-sized units from writes and trims and
output a histogram of how many trims it took to get to errors, and what kind