> I'm building a system with two Apple RAIDs attached. I have hardware > RAID5 configured so no RAIDZ or RAIDZ2, just a basic zpool pointing at > the four LUNs representing the four RAID controllers. For on-going > maintenance, will a zpool scrub be of any benefit?
If some problem is causing data corruption, the scrub would be able to detect it and notify you (though it would not necessarily be able to correct it since most of your data will be non-redundant). That's still of value in many cases. The earlier you know about it, the less data is likely to be affected, and the greater chance you have of being able to repair it through other means (backups, hopefully). Also, in-pool metadata should be redundant (via ditto blocks). Errors in such data can be detected and repaired during a scrub. > From what I've read with this layer of abstration ZFS is only > maintaining the metadata and not the actual data on the drives. I'm not sure what "maintaining" means here. The actual data is still tracked and checksummed. But since it is non-redundant, ZFS does not have sufficient information to repair the data if errors are found. > What's the best practice to keep the data healthy? (scrub, > import/export, etc..) Scrub can notify you of problems that are seen. Backups are also important. Otherwise, keep the underlying storage as healthy as possible. > Also, where are the replicas of the metadata stored in this > configuration? The pool configuration is stored on disks that are members of the pool, and you have four "disks". Because of ditto blocks, the in-pool metadata is duplicated (or triplicated). Since you have multiple luns in your pool, the redundant copies should be stored on different luns. > Can that be backed up? Not separately from the data, no. And I don't know that there's anything useful that could be done with it even if you did. You can't recreate a pool in a way to read old data from it.... -- Darren Dunham [EMAIL PROTECTED] Senior Technical Consultant TAOS http://www.taos.com/ Got some Dr Pepper? San Francisco, CA bay area < This line left intentionally blank to confuse you. > _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
