NAS pSEO Landing
Estimate usable TB, parity overhead, and fault tolerance for 10x 18TB in RAID 6. Includes reserve planning for NAS and homelab arrays.
Raw Capacity
180.00 TB
Usable Capacity
129.60 TB
Fault Tolerance
2 drives
Efficiency
80.0%
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 | 145.80 TB | 1 drive | 90.0% |
| RAID 6 | 129.60 TB | 2 drives | 80.0% |
| RAID 10 | 81.00 TB | 1 drive per mirror pair* | 50.0% |
| RAID-Z1 | 145.80 TB | 1 drive | 90.0% |
| RAID-Z2 | 129.60 TB | 2 drives | 80.0% |
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 setup can tolerate 2 drives. Real-world survivability depends on mirror placement, rebuild stress, and drive health.
No. Use this page for pre-purchase sizing, then validate with workload benchmarks, SMART health policy, and a tested restore plan.
This NAS planning scenario estimates 129.60 TB usable after a 10% reserve from 180.00 TB raw.