NAS pSEO Landing
Region Focus · US
Estimate usable TB, parity, and fault tolerance for US homelab buyers using 6x 20TB in RAID-Z1.
Raw Capacity
120.00 TB
Usable Capacity
90.00 TB
Fault Tolerance
1 drive
Efficiency
83.3%
ZFS single-parity equivalent of RAID 5; common for smaller homelab pools. This scenario applies a 10% filesystem reserve.
Run Interactive Calculator →| Mode | Usable | Tolerance | Efficiency |
|---|---|---|---|
| RAID 5 | 90.00 TB | 1 drive | 83.3% |
| RAID 6 | 72.00 TB | 2 drives | 66.7% |
| RAID 10 | 54.00 TB | 1 drive per mirror pair* | 50.0% |
| RAID-Z1 | 90.00 TB | 1 drive | 83.3% |
| RAID-Z2 | 72.00 TB | 2 drives | 66.7% |
US buyers often evaluate frequent pricing swings and promo cycles. Capacity planning should account for staged purchases instead of one-time all-disk upgrades.
Planning metric that compares real usable capacity after reserve and parity.
Seasonal pricing period used for phased drive purchasing strategies.
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.
For US homelab buyers, this NAS planning scenario estimates 90.00 TB usable after a 10% reserve from 120.00 TB raw.
This setup can tolerate 1 drive. Real-world survivability depends on mirror placement, rebuild stress, and drive health.