RAID levels

xiRAID Opus enables you to create RAIDs of levels 0, 1, 5, 6, 7, 10, 50, 60 and 70.

RAID 0 – interleaving data blocks without mirroring (replication of data across disks) or parity. The data blocks are distributed across several drives. The distribution results parallel IO mode that provides high performance. Due to the lack of redundancy, RAID 0 doesn’t provide data reliability – the failure of one drive in RAID leads to the data corruption. RAID 0 requires at least 2 drives.

RAID 1 – mirroring without parity or striping. The data is mirrored on all drives of the RAID, and the RAID size can only be of the smallest drive size. Random read performance of a RAID 1 may equal up to the sum of each member's performance, while the write performance remains at the level of a single slowest drive. RAID 1 requires at least 2 drives.

RAID 5 – interleaving blocks with distributed parity. RAID 5 requires at least three drives. RAID 5 sustains the complete failure of one drive and provides a minimal degree of reliability.

RAID 6 – interleaving blocks with double parity distribution. RAID 6 requires at least four drives. RAID 6 can sustain the complete failure of two drives. Redundant parity information provides additional time to restore redundancy without loss of information.

RAID 7 – interleaving blocks with triple parity distribution. RAID 7 requires at least four drives. It is RAID 6 analog, but has a higher degree of reliability: three checksums are calculated using different algorithms, the capacity of three drives is allocated for checksums. Thus, the RAID 7 can sustain the complete failure of three drives.