RAID 5 vs RAID 6
This guide supports the Storage Calculators shelf by explaining the decision behind the calculator. Calculator pages give you the number; guides help you understand when the number is good enough and when a different setup is safer.
What this guide covers
RAID 5 gives more usable space, while RAID 6 gives dual-parity protection during rebuild risk. The practical goal is to choose storage with enough usable capacity, enough failure tolerance, and enough headroom for growth without pretending that one formula fits every device or workload.
Decision checklist
- Define the usable capacity you actually need.
- Choose whether redundancy, speed, cost, or simplicity matters most.
- Account for hot spares, filesystem overhead, decimal-vs-binary units, and backup needs.
- Compare at least two scenarios with the calculators before buying hardware.