docs: add documentation for sg ioengine WRITE SAME, WRITE AND VERIFY command support

[fio.git] / fio.1

diff --git a/fio.1 b/fio.1
index 7d5d8be60c056c6f2b8a8e61d7b92db90c0e7302..ce3585a43a6660bdda2e45000bea7e9a9825c6ec 100644 (file)
--- a/fio.1
+++ b/fio.1
@@ -1828,6 +1828,33 @@ unit access (fua) flag. Default: 0.
 .BI (sg)writefua \fR=\fPbool
 With writefua option set to 1, write operations include the force
 unit access (fua) flag. Default: 0.
 .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
 .SS "I/O depth"
 .TP
 .BI iodepth \fR=\fPint