On Tue, 22 Dec 2009, Marty Scholes wrote:
That's not entirely true, is it? * RAIDZ is RAID5 + checksum + COW * RAIDZ2 is RAID6 + checksum + COW * A stack of mirror vdevs is RAID10 + checksum + COW
These are layman's simplifications that no one here should be comfortable with.
Zfs borrows proven data recovery technologies from classic RAID but the data layout on disk is not classic RAID, or even close to it. Metadata and file data are handled differently. Metadata is always duplicated, with the most critical metadata being strewn across multiple disks. Even "mirror" disks are not really mirrors of each other.
Earlier in this discussion thread someone claimed that if a raidz disk was lost that the pool was then just one data error away from total disaster, but that is not normally true due to the many other things that zfs does.
Bob -- Bob Friesenhahn bfrie...@simple.dallas.tx.us, 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
