KB 10294 Does Promise implement RAID 0+1 or 1+0?
As it is understood, Promise’s implementation is 0+1. However functionality is
that of RAID 1+0, for example: When one disk in the striped set is forced
offline or fails, its disk mirror will take over IO, it is not treated like a RAID 0 stripe under the mirror. Though highly improbable, it is possible to lose
10 drives in a 20 drive RAID 0+1 or 1+0. Functionally the two are synonymous within the
Promise RAID architecture.
RAID
10 provides high availability by combining features of RAID 0 and RAID 1.
