NAS pSEO Landing
Region Focus · APAC
Estimate usable TB, parity, and fault tolerance for APAC homelab buyers using 8x 16TB in RAID-Z2.
Raw Capacity
128.00 TB
Usable Capacity
86.40 TB
Fault Tolerance
2 drives
Efficiency
75.0%
Popular TrueNAS default for medium arrays; dual-parity with good safety margin. This scenario applies a 10% filesystem reserve.
Run Interactive Calculator →| Mode | Usable | Tolerance | Efficiency |
|---|---|---|---|
| RAID 5 | 100.80 TB | 1 drive | 87.5% |
| RAID 6 | 86.40 TB | 2 drives | 75.0% |
| RAID 10 | 57.60 TB | 1 drive per mirror pair* | 50.0% |
| RAID-Z1 | 100.80 TB | 1 drive | 87.5% |
| RAID-Z2 | 86.40 TB | 2 drives | 75.0% |
APAC builders frequently compare availability windows and procurement variance, which makes robust fallback capacity and staged scaling useful in practice.
Regional differences in disk availability and replacement lead times.
Policy of keeping spare disks available to reduce recovery delay risk.
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.
For long-lived NAS pools, resiliency first is usually safer. Capacity can be expanded later, while a risky parity choice can force migration sooner.
For APAC homelab buyers, this NAS planning scenario estimates 86.40 TB usable after a 10% reserve from 128.00 TB raw.