Jeff, what do you mean by "disks that simply blow off write ordering."? My experience is that most enterprise disks are some flavor of SCSI, and host SCSI drivers almost ALWAYS use simple queue tags, implying the target is free to re-order the commands for performance. Are talking about something else, or does ZFS request Order Queue Tags on certain commands?
Charles Jeff Bonwick wrote: >> There is no substitute for cord-yank tests - many and often. The >> weird part is, the ZFS design team simulated millions of them. >> So the full explanation remains to be uncovered? >> > > We simulated power failure; we did not simulate disks that simply > blow off write ordering. Any disk that you'd ever deploy in an > enterprise or storage appliance context gets this right. > > The good news is that ZFS is getting popular enough on consumer-grade > hardware. The bad news is that said hardware has a different set of > failure modes, so it takes a bit of work to become resilient to them. > This is pretty high on my short list. > > Jeff > _______________________________________________ > 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
