RAID Calculator
Planning a disk array? Enter your RAID level, number of disks, and disk size to see usable capacity, storage efficiency, and fault tolerance at a glance. Covers RAID 0, 1, 5, 6, and 10.
RAID levels at a glance:
- RAID 0 (Striping) -- splits data across all disks for speed. No redundancy. If one disk dies, everything is gone.
- RAID 1 (Mirroring) -- duplicates data on every disk. Maximum safety, but you only get the capacity of one drive.
- RAID 5 (Striping + Parity) -- distributes parity across all disks. Survives one disk failure. Needs at least 3 disks.
- RAID 6 (Double Parity) -- like RAID 5 but survives two simultaneous disk failures. Needs at least 4 disks.
- RAID 10 (Mirrored Stripes) -- combines RAID 1 mirrors into a RAID 0 stripe. Fast reads, survives one failure per mirror pair. Needs at least 4 disks (even number).
Choosing a RAID level:
- Need pure speed with no safety net? RAID 0.
- Need maximum reliability for critical data? RAID 1 or RAID 10.
- Want a balance of capacity, speed, and safety? RAID 5 is the most popular choice.
- Running a server where downtime is expensive? RAID 6 gives you room to lose two disks while you source replacements.
Remember: RAID is not a backup. It protects against hardware failure, not accidental deletion, ransomware, or controller failure. Always keep separate backups.