On 09/24/2010 07:50 PM, Digimer wrote: > Raid 10 requires 4 drives. First you would make two RAID 0 arrays, then > create a third array that is RAID 1 using the two RAID 0 arrays for it's > devices. > > With only two drives, your option is RAID 1 (mirroring - proper > redundancy) or RAID 0 (striping only - lose one drive and you lose *all* > data). > > That's 0+1 not 1+0. 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. -- Benjamin Franz