this document include SCSI disk and SCSI device parameters, add cache_type firstly, other parameters will be added later. Signed-off-by: Weiping Zhang <zhangweiping@xxxxxxxxxxxxxxx> --- Documentation/scsi/sd-parameters.txt | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) create mode 100644 Documentation/scsi/sd-parameters.txt diff --git a/Documentation/scsi/sd-parameters.txt b/Documentation/scsi/sd-parameters.txt new file mode 100644 index 0000000..88ea9a2 --- /dev/null +++ b/Documentation/scsi/sd-parameters.txt @@ -0,0 +1,23 @@ +Linux SCSI sd Parameters +============================================================ + +scsi disk +---------------------------------------- +Path: /sys/block/sdx/device/scsi_disk/x:x:x:x/* + +* Name: cache_type +* Description: enable/disable write&read cache + +Encoding | WCE RCD | Write_cache Read_cache +------------------------------------------------------------- +write through | 0 0 | off on +none | 0 1 | off off +write back | 1 0 | on on +write back, no read (daft) | 1 1 | on off + +For "temporary", it only change request_queue's flag, not send +any command to disk, so actually disk'cache doesn't changed yet. + +* Usage: +echo "write back" > cache_type +echo "temporary write back" > cache_type -- 2.9.4
