NAS pSEO Landing
Estimate usable TB, parity overhead, and fault tolerance for 3x 12TB in RAID 5. Includes reserve planning for NAS and homelab arrays.
Raw Capacity
36.00 TB
Usable Capacity
21.60 TB
Fault Tolerance
1 drive
Efficiency
66.7%
Balanced capacity and redundancy, but rebuild stress can be high on large disks. This scenario applies a 10% filesystem reserve.
Run Interactive Calculator →| Mode | Usable | Tolerance | Efficiency |
|---|---|---|---|
| RAID 5 | 21.60 TB | 1 drive | 66.7% |
| RAID 6 | N/A | N/A | N/A |
| RAID 10 | N/A | N/A | N/A |
| RAID-Z1 | 21.60 TB | 1 drive | 66.7% |
| RAID-Z2 | N/A | N/A | N/A |
This setup can tolerate 1 drive. Real-world survivability depends on mirror placement, rebuild stress, and drive health.
This NAS planning scenario estimates 21.60 TB usable after a 10% reserve from 36.00 TB raw.
No. Use this page for pre-purchase sizing, then validate with workload benchmarks, SMART health policy, and a tested restore plan.
It can be practical, but larger drives increase rebuild windows. Validate parity choice and backup policy before committing to the final layout.