RAID levels

RAID levels are the possible configurations of a RAIDdisk array. RAID is an acronym for redundant array of independent disks (originally redundant array of inexpensive disks). Different RAID levels define how data is distributed across multiple storage devices and whether techniques such as data striping, disk mirroring, or parity are used to provide increased performance, storage capacity, or fault tolerance.

The term "RAID level" does not imply a hierarchy of performance or reliability. The numerical designations primarily identify different data layouts and redundancy schemes. Standard RAID levels are defined by the Storage Networking Industry Association (SNIA) in the (DDF) standard, while numerous nested and non-standard implementations have also been developed.