NAS pSEO Landing
Estimate usable TB, parity overhead, and fault tolerance for 5x 20TB in RAID 6. Includes reserve planning for NAS and homelab arrays.
Raw Capacity
100.00 TB
Usable Capacity
54.00 TB
Fault Tolerance
2 drives
Efficiency
60.0%
Safer for larger arrays with dual parity, at the cost of one extra parity disk. This scenario applies a 10% filesystem reserve.
Run Interactive Calculator →| Mode | Usable | Tolerance | Efficiency |
|---|---|---|---|
| RAID 5 | 72.00 TB | 1 drive | 80.0% |
| RAID 6 | 54.00 TB | 2 drives | 60.0% |
| RAID 10 | N/A | N/A | N/A |
| RAID-Z1 | 72.00 TB | 1 drive | 80.0% |
| RAID-Z2 | 54.00 TB | 2 drives | 60.0% |
For long-lived NAS pools, resiliency first is usually safer. Capacity can be expanded later, while a risky parity choice can force migration sooner.
This NAS planning scenario estimates 54.00 TB usable after a 10% reserve from 100.00 TB raw.
It can be practical, but larger drives increase rebuild windows. Validate parity choice and backup policy before committing to the final layout.
This setup can tolerate 2 drives. Real-world survivability depends on mirror placement, rebuild stress, and drive health.