> And don't do it that way. > > If you have a single drive failure with RAID 0+1 you've lost *all* of > your redundancy - one more failure and you are dead. If you create two > RAID1 sets and then strip them into a RAID0 you get pretty much the same > performance and space efficiency characteristics, but if you have a > drive failure you still have partial redundancy. You could actually take > a *second* drive failure as long as it was in the other RAID1 pair. With > 4 drives raid0+1 can only survive 1 drive failure. With 4 drives in raid > 1+0 you can survive an average of 1.67 drive failures. Indeed. This article explains the odds of loosing data with RAID 1+0 vs 0+1: Why is RAID 1+0 better than RAID 0+1? http://www.aput.net/~jheiss/raid10/