On Wed, 16 Apr 2008, David Magda wrote: >> RAID5 and RAID6 rebuild the entire disk while raidz1 and raidz2 only >> rebuild existing data blocks so raidz1 and raidz2 are less likely to >> experience media failure if the pool is not full. > > While the failure statistics may be different, I think any comparison would > be "apples-to-apples".
Note that if the pool is only 10% full, then it is 10X less likely to experience a media failure during rebuild than traditional RAID-5/6 with the same disks. In addition to this, zfs replicates metadata and writes the copies to different disks depending on the redundancy strategy. A traditional filesystem on traditional RAID does not have this same option (having no knowledge of the underlying disks) even though it does replicate some essential metadata (multiple super blocks). Since my time on this list, the vast majority of reports have been of the nature "my pool did not come back up after system crash" or "the pool stopped responding" and not that their properly redundant pool lost some user data. This indicates that the storage principles are quite sound but the implementation (being relatively new) still has a few rough edges. Bob ====================================== Bob Friesenhahn [EMAIL PROTECTED], http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
