RAID 10 configuration

In RAID 10 (RAID 1+0) configurations, data written to a physical disk is duplicated to a second disk. The usable capacity is C x (n/2) where C is the physical disk capacity with n drives in the storage array. When the storage array contains only two physical drives, the fault-tolerance is known as RAID 1.

Storage arrays with more than two physical drives are known as RAID 10 or RAID 1+0. If a physical drive fails, the remaining drive in a mirrored pair still provides access to all data. Multiple drives in the storage array can fail without incurring data loss, provided that no two failed drives belong to the same mirrored pair. The total drive count must be an increment of 2 when adding capacity to an existing mirrored configuration.

This fault tolerance configuration allows high performance and high resiliency at the expense of usable capacity. For environments where high performance and reliability are required, this storage array configuration is recommended. This array allows data access even if half of the physical drives in a storage array fail, provided that no two failed drives belong to the same mirrored pair.