RAID, explained
RAID combines drives into an arrangement intended for capacity, performance, redundancy or a combination of those goals.
- The field
- Technical
- Reading time
- 1 minute
- In this entry
- Meaning · relevance · limits
The meaning
RAID combines drives into an arrangement intended for capacity, performance, redundancy or a combination of those goals.
Why it matters
Different levels have different usable capacity and failure characteristics. Ask what the provider actually uses and monitors.
The boundary
Redundancy cannot recover every accidental deletion, ransomware event or application error; keep independent backups.
Availability and recoverability are different jobs
A mirrored storage set can continue operating after a qualifying disk failure, but an accidental deletion or damaged application data may be mirrored too. Use RAID for the intended storage-availability goal and keep versioned backups in a separate failure domain. The exact array level determines usable capacity and tolerated failures.
- RAID 1 mirrors data; RAID 0 provides no disk-failure redundancy.
- Test recovery from an independent backup and do not label a snapshot immutable without an enforced retention design.