As hard drive capacities have scaled into massive multi-terabyte sizes, the time required to rebuild a RAID 5 array has stretched from minutes to days. Because the rebuild window is so long, the statistical likelihood of hitting a second drive failure or a URE has skyrocketed.
- The Shift to RAID 6: For modern storage setups using drives larger than 2TB, storage experts strongly discourage RAID 5. RAID 6 (which features dual distributed parity and can survive two simultaneous drive failures) is highly preferred.
- Backup Reality: RAID 5 only protects against a single hardware failure. It offers zero protection against ransomware, accidental deletion, fire, or catastrophic controller failure. A separate backup is mandatory.
