[CentOS] Raid 10 questions...2 drive

Sat Sep 25 20:11:20 UTC 2010
Miguel Medalha <miguelmedalha at sapo.pt>

> 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/