NAS pSEO Landing
Brand Focus · Unraid
Estimate usable capacity, fault tolerance, and efficiency for Unraid NAS users using 4x 8TB in RAID 6.
Raw Capacity
32.00 TB
Usable Capacity
14.40 TB
Fault Tolerance
2 drives
Efficiency
50.0%
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 | 21.60 TB | 1 drive | 75.0% |
| RAID 6 | 14.40 TB | 2 drives | 50.0% |
| RAID 10 | 14.40 TB | 1 drive per mirror pair* | 50.0% |
| RAID-Z1 | 21.60 TB | 1 drive | 75.0% |
| RAID-Z2 | 14.40 TB | 2 drives | 50.0% |
Unraid users often optimize for incremental growth and flexible disk replacement, where parity planning and usable capacity targets evolve over time rather than all at once.
Dedicated parity disk(s) protecting data disks in the Unraid array model.
Fast SSD/NVMe pool used for writes and application workloads.
Scheduled process that migrates data between cache and array tiers.
No. Use this page for pre-purchase sizing, then validate with workload benchmarks, SMART health policy, and a tested restore plan.
For Unraid users, this NAS planning scenario estimates 14.40 TB usable after a 10% reserve from 32.00 TB raw.
This setup can tolerate 2 drives. Real-world survivability depends on mirror placement, rebuild stress, and drive health.
It can be practical, but larger drives increase rebuild windows. Validate parity choice and backup policy before committing to the final layout.