> Are Netapp using some kind of block checksumming? They provide an option for it, I'm not sure how often it's used.
> If Netapp doesn't do something like [ZFS checksums], that would > explain why there's frequently trouble reconstructing, and point up a > major ZFS advantage. Actually, the real problem is uncorrectable errors on drives. On a 1 TB SATA drive, there's a good chance (over 1%) that at least one block will be unreadable once written. Scrubbing tries to catch these, but if an error develops between the last scrub and the need to read the data as part of reconstruction, you're out of luck. This is the big advantage of RAID-6 / RAIDZ2; the combination of a drive failure and a single-block failure on a second drive won't lead to data loss. This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
