On Wed, Mar 12, 2008 at 09:59:53PM +0000, A Darren Dunham wrote: > It's not *bad*, but as far as I'm concerned, it's wasted space. > > You have to deal with the pool as a whole as having single-disk > redundancy for failure modes. So the fact that one section of it has > two-disk redundancy doesn't give you anything in failure planning. > > And you can't assign filesystems or particular data to that vdev, so the > added redundancy can't be concentrated anywhere.
Well, one can imagine a situation where two different type of disks have different failure probabilities such that the same reliability could be garnered with one using single-parity RAID as with the other using double- parity RAID. That said, it would be a fairly uncommon scenario. Adam -- Adam Leventhal, Fishworks http://blogs.sun.com/ahl _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss