NAS pSEO Landing
Estimate usable TB, parity overhead, and fault tolerance for 10x 20TB in RAID 1. Includes reserve planning for NAS and homelab arrays.
Raw Capacity
200.00 TB
Usable Capacity
18.00 TB
Fault Tolerance
9 drives*
Efficiency
10.0%
Strong redundancy but low capacity efficiency. Great for small, critical datasets. This scenario applies a 10% filesystem reserve.
Run Interactive Calculator →| Mode | Usable | Tolerance | Efficiency |
|---|---|---|---|
| RAID 5 | 162.00 TB | 1 drive | 90.0% |
| RAID 6 | 144.00 TB | 2 drives | 80.0% |
| RAID 10 | 90.00 TB | 1 drive per mirror pair* | 50.0% |
| RAID-Z1 | 162.00 TB | 1 drive | 90.0% |
| RAID-Z2 | 144.00 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.
No. Use this page for pre-purchase sizing, then validate with workload benchmarks, SMART health policy, and a tested restore plan.
This setup can tolerate 9 drives*. Real-world survivability depends on mirror placement, rebuild stress, and drive health.
This NAS planning scenario estimates 18.00 TB usable after a 10% reserve from 200.00 TB raw.