On 14 June, 2008 - zfsmonk sent me these 0,7K bytes: > Mentioned on > http://www.solarisinternals.com/wiki/index.php/ZFS_Best_Practices_Guide > is the following: "ZFS works well with storage based protected LUNs > (RAID-5 or mirrored LUNs from intelligent storage arrays). However, > ZFS cannot heal corrupted blocks that are detected by ZFS checksums." > > based upon that, if we have LUNs already in RAID5 being served from > intelligent storage arrays, is it any benefit to create the zpool in a > mirror if zfs can't heal any corrupted blocks? Or would we just be > wasting disk space?
Let's say you have a raid thing called A.. If you use that as ZFS storage and ZFS detects bit errors in it, there's not much it can do other than say "your storage sucks". If you have another raid thing called B and you mirror A and B through ZFS.. Then A comes along and flips some bits again.. then ZFS checks B, sees that it's still correct and fixes A. A might be intelligent storage and can cope with a disk dying, but if A delivers bit errors up to ZFS - then ZFS can't fix it. If A is actually dumb storage and you leave the raid part to ZFS, then it can fix. /Tomas -- Tomas Ögren, [EMAIL PROTECTED], http://www.acc.umu.se/~stric/ |- Student at Computing Science, University of Umeå `- Sysadmin at {cs,acc}.umu.se _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
