On Thu, 2006-06-29 at 03:40, Nicolas Williams wrote: > But Joe makes a good point about RAID-Z and iSCSI. > > It'd be nice if RAID HW could assist RAID-Z, and it wouldn't take much > to do that: parity computation on write, checksum verification on read > and, if the checksum verification fails, combinarotial reconstruction on > read. The ZFS system (iSCSI client) would still have to verify the > checksum on read... > > ...but leaving parity computation/reconstruction to the iSCSI server > would greatly cut down the amount of I/O needed for RAID-Z to something > similar to that needed for HW RAID-5. > > Sure, I don't expect HW-assisted RAID-Z anytime soon, nor iSCSI > extensions for server-assisted RAID-Z. But at least iSCSI protocol > extensions could be pursued now.
But - This still fails to address the design concept of ZFS's end to end checksumming, and fails to address things gong bad over the system's hardware bus, the IO card and the Fibre... So - It's not nearly the same level of protection, IMO. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
