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3x 6TB RAID-Z1 Calculator

Estimate usable capacity, fault tolerance, and efficiency for 3x 6TB in RAID-Z1 with reserve best practices.

Capacity Snapshot

Raw Capacity

18.00 TB

Usable Capacity

10.80 TB

Fault Tolerance

1 drive

Efficiency

66.7%

ZFS single-parity equivalent of RAID 5; common for smaller homelab pools. This scenario applies a 10% filesystem reserve.

Run Interactive Calculator →

Alternative Mode Comparison

Mode Usable Tolerance Efficiency
RAID 5 10.80 TB 1 drive 66.7%
RAID 6 N/A N/A N/A
RAID 10 N/A N/A N/A
RAID-Z1 10.80 TB 1 drive 66.7%
RAID-Z2 N/A N/A N/A

Related Long-Tail Calculators

2x 4TB RAID 1 2x 6TB RAID 1 2x 8TB RAID 1 2x 10TB RAID 1 2x 12TB RAID 1 2x 14TB RAID 1 2x 16TB RAID 1 2x 18TB RAID 1 2x 20TB RAID 1 3x 4TB RAID 1 3x 4TB RAID 5 3x 4TB RAID-Z1 3x 6TB RAID 1 3x 6TB RAID 5 3x 6TB RAID-Z1 3x 8TB RAID 1

FAQ

Why include a 10% reserve when planning NAS storage headroom?

Keeping free space improves filesystem behavior for snapshots, metadata, and write performance. Full arrays often perform worse and rebuild more slowly.

Can this calculator replace real-world benchmark and rebuild testing?

No. Use this page for pre-purchase sizing, then validate with workload benchmarks, SMART health policy, and a tested restore plan.

How much effective storage does 3x 6TB RAID-Z1 provide?

This NAS planning scenario estimates 10.80 TB usable after a 10% reserve from 18.00 TB raw.

Is RAID-Z1 still viable with 6TB drives?

It can be practical, but larger drives increase rebuild windows. Validate parity choice and backup policy before committing to the final layout.