What is RAID 10?
In a RAID 1+0 implementation, data is striped across several drives (RAID 0). This complete array of drives is mirrored by one or more arrays of drives. (This latter configuration can be termed a mirror of stripes.) RAID 10 offers the data transfer advantages of striped arrays and the data accessibility features of mirrored arrays. System performance during a drive rebuild is also better than that of parity-based arrays, since data does not need to be regenerated from parity information, but simply copied from a surviving drive. The cost of a RAID 10 array is the same as that of a RAID 1 array, as both arrays require that at least two complete sets of data be stored.