.TP
.B pmemblk
Read and write using filesystem DAX to a file on a filesystem
-mounted with DAX on a persistent memory device through the NVML
+mounted with DAX on a persistent memory device through the PMDK
libpmemblk library.
.TP
.B dev\-dax
Read and write using device DAX to a persistent memory device (e.g.,
-/dev/dax0.0) through the NVML libpmem library.
+/dev/dax0.0) through the PMDK libpmem library.
.TP
.B external
Prefix to specify loading an external I/O engine object file. Append
.TP
.B libpmem
Read and write using mmap I/O to a file on a filesystem
-mounted with DAX on a persistent memory device through the NVML
+mounted with DAX on a persistent memory device through the PMDK
libpmem library.
.SS "I/O engine specific parameters"
In addition, there are some parameters which are only valid when a specific
.BI (sg)writefua \fR=\fPbool
With writefua option set to 1, write operations include the force
unit access (fua) flag. Default: 0.
+.TP
+.BI (sg)sg_write_mode \fR=\fPstr
+Specify the type of write commands to issue. This option can take three
+values:
+.RS
+.RS
+.TP
+.B write (default)
+Write opcodes are issued as usual
+.TP
+.B verify
+Issue WRITE AND VERIFY commands. The BYTCHK bit is set to 0. This
+directs the device to carry out a medium verification with no data
+comparison. The writefua option is ignored with this selection.
+.TP
+.B 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
+specifies the amount of data written with each command. However, the
+amount of data actually transferred to the device is equal to the
+device's block (sector) size. For a device with 512 byte sectors,
+blocksize=8k will write 16 sectors with each command. fio will still
+generate 8k of data for each command butonly the first 512 bytes will
+be used and transferred to the device. The writefua option is ignored
+with this selection.
+
.SS "I/O depth"
.TP
.BI iodepth \fR=\fPint
still respecting ordering. The result is the same I/O pattern to a given
device, but different timings.
.TP
+.BI replay_time_scale \fR=\fPint
+When replaying I/O with \fBread_iolog\fR, fio will honor the original timing
+in the trace. With this option, it's possible to scale the time. It's a
+percentage option, if set to 50 it means run at 50% the original IO rate in
+the trace. If set to 200, run at twice the original IO rate. Defaults to 100.
+.TP
.BI replay_redirect \fR=\fPstr
While replaying I/O patterns using \fBread_iolog\fR the default behavior
is to replay the IOPS onto the major/minor device that each IOP was recorded
Scale sector offsets down by this factor when replaying traces.
.SS "Threads, processes and job synchronization"
.TP
+.BI replay_skip \fR=\fPstr
+Sometimes it's useful to skip certain IO types in a replay trace. This could
+be, for instance, eliminating the writes in the trace. Or not replaying the
+trims/discards, if you are redirecting to a device that doesn't support them.
+This option takes a comma separated list of read, write, trim, sync.
+.TP
.BI thread
Fio defaults to creating jobs by using fork, however if this option is
given, fio will create jobs by using POSIX Threads' function
the verify will be of the newly written data.
.RE
.TP
-.BI verifysort \fR=\fPbool
-If true, fio will sort written verify blocks when it deems it faster to read
-them back in a sorted manner. This is often the case when overwriting an
-existing file, since the blocks are already laid out in the file system. You
-can ignore this option unless doing huge amounts of really fast I/O where
-the red\-black tree sorting CPU time becomes significant. Default: true.
-.TP
-.BI verifysort_nr \fR=\fPint
-Pre\-load and sort verify blocks for a read workload.
-.TP
.BI verify_offset \fR=\fPint
Swap the verification header with data somewhere else in the block before
writing. It is swapped back before verifying.
projects / fio.git / blobdiff