Hello Philip, Thursday, June 29, 2006, 2:58:41 AM, you wrote:
PB> Erik Trimble wrote: >> >> Since the best way to get this is to use a Mirror or RAIDZ vdev, I'm >> assuming that the proper way to get benefits from both ZFS and HW RAID >> is the following: >> >> (1) ZFS mirror of HW stripes, i.e. "zpool create tank mirror >> hwStripe1 hwStripe2" >> (2) ZFS RAIDZ of HW mirrors, i.e. "zpool create tank raidz hwMirror1, >> hwMirror2" >> (3) ZFS RAIDZ of HW stripes, i.e. "zpool create tank raidz hwStripe1, >> hwStripe2" >> >> mirrors of mirrors and raidz of raid5 is also possible, but I'm pretty >> sure they're considerably less useful than the 3 above. >> >> Personally, I can't think of a good reason to use ZFS with HW RAID5; >> case (3) above seems to me to provide better performance with roughly >> the same amount of redundancy (not quite true, but close). >> PB> I almost regret extending this thread more :-) but I havent seen anyone PB> spell out one thing in simple language, so i'll attempt to do that now. PB> #2 is incredibly wasteful of space, so I'm not going to address it. it is PB> highly redundant, that's great. if you need it, do it. I'm more concerned PB> with the concept of PB> zfs of two hardware raid boxes that have internal disk redundancy PB> vs PB> zfs of two hardware raid boxes that are pure stripes (raid 0) PB> (doesnt matter if using zfs mirror vs raidz to me, for this aspect of things) PB> The point that I think people should remember, is that if you lose a drive PB> in a pure raid0 configuration... your time to recover that hwraid unit and PB> bring it back to full operation in the filesystem.. is HUGE. PB> It will most likely be unacceptibly long. hours if not days, for a decent PB> sized raid box. Not really. You can create many smaller raid-0 luns in one array and then do raid-10 in zfs. That should also expand your available depth queue and minimize impact of resilvering. Storage capacity would still be the same. -- Best regards, Robert mailto:[EMAIL PROTECTED] http://milek.blogspot.com _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
