A question regarding zfs_nocacheflush: The Evil Tuning Guide says to only enable this if every device is protected by NVRAM. However, is it safe to enable zfs_nocacheflush when I also have local drives (the internal system drives) using ZFS, in particular if the write cache is disabled on those drives? What I have is a local zfs pool from the free space on the internal drives, so I''m only using a partition and the drive''s write cache should be off, so my theory here is that zfs_nocacheflush shouldn''t have any effect because there''s no drive cache in use... -- -Peter Tribble http://www.petertribble.co.uk/ - http://ptribble.blogspot.com/
Hello Peter,
Wednesday, July 30, 2008, 9:19:30 AM, you wrote:
PT> A question regarding zfs_nocacheflush:
PT> The Evil Tuning Guide says to only enable this if every device is
PT> protected by NVRAM.
PT> However, is it safe to enable zfs_nocacheflush when I also have
PT> local drives (the internal system drives) using ZFS, in particular if
PT> the write cache is disabled on those drives?
PT> What I have is a local zfs pool from the free space on the internal
PT> drives, so I''m only using a partition and the drive''s
write cache
PT> should be off, so my theory here is that zfs_nocacheflush
shouldn''t
PT> have any effect because there''s no drive cache in use...
Should be fine in that case.
--
Best regards,
Robert Milkowski mailto:milek at task.gda.pl
http://milek.blogspot.com
Peter Tribble writes: > A question regarding zfs_nocacheflush: > > The Evil Tuning Guide says to only enable this if every device is > protected by NVRAM. > > However, is it safe to enable zfs_nocacheflush when I also have > local drives (the internal system drives) using ZFS, in particular if > the write cache is disabled on those drives? > > What I have is a local zfs pool from the free space on the internal > drives, so I''m only using a partition and the drive''s write cache > should be off, so my theory here is that zfs_nocacheflush shouldn''t > have any effect because there''s no drive cache in use... > Seems plausible, But I''d check that the caches are indeed off using format -e. -r > -- > -Peter Tribble > http://www.petertribble.co.uk/ - http://ptribble.blogspot.com/ > _______________________________________________ > zfs-discuss mailing list > zfs-discuss at opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss