> It's the block checksum that requires reading all of the disks. If > ZFS stored sub-block checksums for the RAID-Z case then short reads > could often be satisfied without reading the whole block (and all > disks).
What happens when a sub-block is missing (single disk failure)? Surely it doesn't have to discard the entire checksum and simply trust the remaining blocks? Also, even if it could read the data from a subset of the disks, isn't it a feature that every read is also verifying the parity for correctness/silent corruption? I'm assuming that any "short-read" optimization wouldn't be able to perform that check. -- 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
