Hey James, > Personally, I think mirroring is safer (and 3 way mirroring) than raidz/z2/5. > All my "boot from zfs" systems have 3 way mirrors root/usr/var disks (using > 9 disks) but all my data partitions are 2 way mirrors (usually 8 disks or > more and a spare.)
Double-parity (or triple-parity) RAID are certainly more resilient against some failure modes than 2-way mirroring. For example, bit errors can arise at a certain rate from disks. In the case of a disk failure in a mirror, it's possible to encounter a bit error such that data is lost. I recently wrote an article for ACM Queue that examines recent trends in hard drives and makes the case for triple-parity RAID. It's at least peripherally relevant to this conversation: http://blogs.sun.com/ahl/entry/acm_triple_parity_raid Adam -- Adam Leventhal, Fishworks http://blogs.sun.com/ahl _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
