**write**
Sequential writes.
**trim**
- Sequential trims (Linux block devices only).
+ Sequential trims (Linux block devices and SCSI
+ character devices only).
**randread**
Random reads.
**randwrite**
Random writes.
**randtrim**
- Random trims (Linux block devices only).
+ Random trims (Linux block devices and SCSI
+ character devices only).
**rw,readwrite**
Sequential mixed reads and writes.
**randrw**
ioctl, or if the target is an sg character device we use
:manpage:`read(2)` and :manpage:`write(2)` for asynchronous
I/O. Requires :option:`filename` option to specify either block or
- character devices.
+ character devices. This engine supports trim operations.
The sg engine includes engine specific options.
**null**
the force unit access (fua) flag. Default is 0.
.. option:: sg_write_mode=str : [sg]
+
Specify the type of write commands to issue. This option can take three values:
**write**