RAID 1+0: Striped Mirrors

The goal of RAID 1+0 is to double performance and capacity while allowing slightly more fault tolerance than RAID-5:

Data is striped (RAID 0) over mirrored sets (RAID 1) of drives for fast redundancy.

RAID 1+0 requires four drives. With four drives, two mirrors are created of two drives each, and those two mirrors are then striped. This allows one drive from each mirror to fail, but failure of both drives of a mirrored pair fails the RAID.

Striping hardware mirrors

A simple way to create a RAID 1+0 mirror is to stripe two hardware-based RAID 1 mirror enclosures, such as the OWC Mercury Elite Pro Dual.

The concept can be extended to stripe 2/3/4/etc RAID-1 mirrors, thus raising performance to higher and higher levels while having fault tolerance within each hardware mirror enclosure. However, the more stripes used, the more the risk of a double-fault within one enclosure. A triple stripe RAID 1+0 carries the concept about as far as it makes sense to go in most cases.

RAID-5 vs 3X RAID-0 stripe vs 4X RAID-0 stripe
(SoftRAID 5 beta)

Creating a software RAID 1+0

Create a 4-drive RAID 1+0 volume Master of capacity 4TB.

Creating a RAID 1+0 with SoftRAID 5