Opened 12 years ago
Closed 12 years ago
#250 closed enhancement (fixed)
implement -g/-s wcache and lookahead for the SCSI drvies
| Reported by: | Alex Samorukov | Owned by: | somebody |
|---|---|---|---|
| Priority: | minor | Milestone: | Release 6.1 |
| Component: | all | Version: | 6.0 |
| Keywords: | scsi | Cc: |
Description (last modified by )
Most of SCSI/SAS drives are supporting cache control, so it is possible to implement this functionality. This should help a lot for SAS drives behind the RAID - some of them turning off write cache if drive is not "native".
Tested on scsi, megaraid and cciss device types on Linux. It was found that cciss silently filtering MODE SELECT command, so actual values are not changed. On megaraid and direct connection everything works as expected.
Change History (2)
comment:1 by , 12 years ago
comment:2 by , 12 years ago
| Description: | modified (diff) |
|---|---|
| Milestone: | → Release 6.1 |
| Resolution: | → fixed |
| Status: | new → closed |
Implemented in r3703-3708. Instead of using "lookahead" new "rcache" setting was added, because "readahead" has very different meaning.
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corresponding settings are "Writeback Cache Enable" (WCE) and clear "Read Cache Disable" (RCD) bits in mode page CACHING_PAGE (0x08)