RAID (Redundant Array of Independent Discs)

A method of storing data on servers that usually combines multiple hard drives into one logical unit thereby increasing capacity, reliability and backup capability. RAID systems may vary in levels of redundancy, with no redundancy being a single, non-mirrored disc as level 0, two discs that mirror each other as level 1, on up, with level 5 being one of the most common. RAID systems are more complicated to copy and restore..”