Also known as: Redundant Array of Independent Disks
RAID (Redundant Array of Independent Disks) combines multiple physical drives into one logical unit to gain redundancy, performance, or both — so data can survive a disk failure or be read and written faster.1
Overview
RAID uses three basic techniques, mixed in different levels. Striping spreads data across drives for speed (RAID 0, no redundancy). Mirroring keeps identical copies so either drive can fail (RAID 1). Parity stores recovery information that lets the array rebuild a lost drive (RAID 5 tolerates one failure, RAID 6 tolerates two). Combined levels like RAID 10 mirror and stripe together. A key caveat: RAID protects against drive failure, not against deletion, corruption, or disaster — it is not a backup.
Where it fits
RAID is the foundation of reliable data storage in network-attached storage, servers, and the data center, and it underpins high availability at the disk level. Built from ordinary hard disk drives or SSDs, a small mirror is a cheap way to keep a GopherTrunk archive of decoded calls alive through a single disk failure.