> On Dec 1, 2007 7:15 AM, Vincent Fox > > Any reason why you are using a mirror of raid-5 > lun's? > > I can understand that perhaps you want ZFS to be in > control of > rebuilding broken vdev's, if anything should go wrong > ... but > rebuilding RAID-5's seems a little over the top.
Because the decision of our technical leads was that a straight ZFS RAID-10 set made up of individual disks from the 2540 was more risky. A double-disk failure in a mirror pair would hose the pool and when the pool contains email for >10K people this was not acceptable. Another possibility is one of the arrays goes offline now you are running a RAID-0 stripe set and a single-disk fails then you are again dead. The setup we have can survive quite multiple failures and we have seen enough weird events in our career that wee decided to do this. YMMV. Let's move on, I just wanted to describe our setup not start an argument about it. > How about running a ZFS mirror over RAID-0 luns? Then > again, the > downside is that you need intervention to fix a LUN > after a disk goes > boom! But you don't waste all that space :) > > PS: It would be nice to know what the LSI firmware > does (after 15 > years of evolution) to writes into the controller... > it might have > been better to buy JOBD's ... I see Sun will be > releasing some soon > (rumour?) A guy in our group exported the disks as LUNs by the way and ran Bonnie++ and the results were a little better for a straight RAID-10 set of all disks, but not hugely better enough to tip the balance towards it. Not perhaps the best test, but what we had time to do. This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
