NAS planning example
Estimate usable TB, parity overhead, and fault tolerance for 6x 16TB in RAID 5. Includes reserve planning for NAS and homelab arrays.
Planning route
Use this worked example as a numeric starting point, then validate the RAID choice, capacity reserve, hardware plan, and backup path.
Editorial method
The capacity model makes drive count, drive size, RAID layout, and reserve visible. It is a planning aid: it does not predict exact performance, rebuild duration, hardware compatibility, or the probability of data loss for a specific system.
Last reviewed: July 10, 2026. Product links remain neutral category searches until a partner relationship and page-level disclosure are in place.
Raw Capacity
96.00 TB
Usable Capacity
72.00 TB
Fault Tolerance
1 drive
Efficiency
83.3%
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 | 72.00 TB | 1 drive | 83.3% |
| RAID 6 | 57.60 TB | 2 drives | 66.7% |
| RAID 10 | 43.20 TB | 1 drive per mirror pair* | 50.0% |
| RAID-Z1 | 72.00 TB | 1 drive | 83.3% |
| RAID-Z2 | 57.60 TB | 2 drives | 66.7% |
NAS cluster navigation
Related long-tail calculators
Sequential long-tail navigation
FAQ
This setup can tolerate 1 drive. Real-world survivability depends on mirror placement, rebuild stress, and drive health.
Keeping free space improves filesystem behavior for snapshots, metadata, and write performance. Full arrays often perform worse and rebuild more slowly.
For long-lived NAS pools, resiliency first is usually safer. Capacity can be expanded later, while a risky parity choice can force migration sooner.
It can be practical, but larger drives increase rebuild windows. Validate parity choice and backup policy before committing to the final layout.