RAID 5
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RAID 5
RAID 5 (Redundant Array of Independent Disks, Level 5) is a storage configuration that provides data redundancy and improved read performance through the use of block-level striping with distributed parity.
It requires a minimum of three disks and can tolerate the failure of one disk without data loss.
How It Works
RAID 5 stripes data across all disks and stores parity information (used for recovery) distributed evenly among all disks. If a single disk fails, the system can reconstruct the lost data using the remaining data and parity.
| Disk 1 | Disk 2 | Disk 3 | Disk 4 |
|---|---|---|---|
| Data A | Data B | Parity AB | Data C |
| Data D | Parity CD | Data E | Data F |
Advantages
- Efficient storage utilization (usable capacity = N-1 disks)
- Good read performance
- Fault tolerance for one disk failure
- More storage-efficient than RAID 1 or RAID 10
Disadvantages
- Slower write performance due to parity calculations
- Recovery after failure can be slow and risky (especially on large disks)
- Vulnerable to data loss if a second disk fails during rebuild
Common Use Cases
- File servers
- Archival storage
- Medium-performance systems with redundancy requirements
