RAID Levels
From Hardware-wiki
- RAID 0 -- striping. Speed, no redundancy. One disk dies, everything dies.
- RAID 1 -- mirroring. Two disks, one copy. Survives one failure.
- RAID 5 -- striping with parity across 3+ disks. Survives one failure. Rebuilds are slow and stress the remaining disks; with large disks a second failure during rebuild is a real risk.
- RAID 6 -- two parity blocks; survives two failures.
- RAID 10 -- mirrored pairs, striped. Fast, survives one failure per pair.
RAID is not a backup. Say it again. Controllers: Intel Matrix/RST on desktop boards is fine for 0/1; for 5/6 use software RAID (mdadm) or a real HBA.
