RAID 6 definition
RAID 6 is a storage configuration that provides redundancy and fault tolerance using a dual parity method — allowing RAID 6 to withstand the simultaneous failure of two hard drives without data loss.
See also: fault tolerance, data center storage, hot spare
Features of RAID 6
- Dual parity. Unlike RAID 5, which uses single parity, RAID 6 calculates two sets of parity data for each piece of data written.
- Minimum disks. RAID 6 requires a minimum of four hard drives to be set up because of the two parity blocks it uses.
- Capacity: The total available storage capacity in a RAID 6 configuration is the sum of the capacities of all the drives minus the capacities of two parity drives. For instance, if you have a RAID 6 array of five 1TB drives, the total usable capacity will be 3TB (5TB minus the 2TB used for parity).
Usage of RAID 6
- Data Centers. Larger data centers often employ RAID 6 for certain storage arrays, particularly when long rebuild times of large-capacity drives make them vulnerable to a second drive failure during the rebuild process.
- Enterprise storage. Businesses requiring high data security and uptime, such as financial institutions, healthcare organizations, and government agencies, prefer RAID 6 configurations.
- Archival storage. Organizations that store archival data, where it's crucial to prevent data loss over extended periods, might choose RAID 6 for its enhanced fault tolerance.
- Video production. Industries dealing with large video files benefit from RAID 6 because it combines reasonable performance and high redundancy.
- Backup and disaster recovery solutions. Systems dedicated to backup and disaster recovery must ensure data integrity and accessibility is crucial, making RAID 6 an attractive choice.
