Jason J. W. Williams writes: > Hi Jeremy, > > It would be nice if you could tell ZFS to turn off fsync() for ZIL > writes on a per-zpool basis. That being said, I'm not sure there's a > consensus on that...and I'm sure not smart enough to be a ZFS > contributor. :-) > > The behavior is a reality we had to deal with and workaround, so I > posted the instructions to hopefully help others in a similar boat. > > I think this is a valuable discussion point though...at least for us. :-) > > Best Regards, > Jason >
To Summarize: Today, ZFS sends a ioctl to the storage that says flush the write cache, while what it really wants is, make sure data is on stable storage. The Storage should then flush or not the cache depending on if it is considered stable or not (only the storage knows that). Soon ZFS (more precisely SD) will be sending a 'qualified' ioctl to clarify the requested behavior. In parallel, Storage vendor shall be implementing that qualified ioctl. ZFS Customers of third party storage probably have more influence to get those vendors to support the qualified behavior. http://bugs.opensolaris.org/bugdatabase/view_bug.do?bug_id=6462690 With SD fixed and Storage vendor support, there will be no more need to tune anything. -r > On 12/15/06, Jeremy Teo <[EMAIL PROTECTED]> wrote: > > > The instructions will tell you how to configure the array to ignore > > > SCSI cache flushes/syncs on Engenio arrays. If anyone has additional > > > instructions for other arrays, please let me know and I'll be happy to > > > add them! > > > > Wouldn't it be more appropriate to allow the administrator to disable > > ZFS from issuing the write cache enable command during a commit? > > (assuming expensive high end battery backed cache etc etc) > > -- > > Regards, > > Jeremy > > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
