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RAID-Z2 vs RAID 6 Storage Capacity Calculator

Compare usable capacity, fault tolerance, and efficiency between RAID-Z2 and RAID 6 for NAS and homelab arrays.

Comparison Notes

This page compares RAID-Z2 and RAID 6 on identical hardware assumptions to help homelab builders choose between capacity efficiency and fault tolerance.

  • Disk size baseline: 8TB drives
  • Reserve policy: 10% filesystem headroom
  • Use the interactive tool for exact real-world constraints
Open Interactive Planner →

Storage Capacity Table

Drives RAID-Z2 RAID 6 Delta
4x 8TB 14.40 TB 14.40 TB +0.00 TB
6x 8TB 28.80 TB 28.80 TB +0.00 TB
8x 8TB 43.20 TB 43.20 TB +0.00 TB
10x 8TB 57.60 TB 57.60 TB +0.00 TB
12x 8TB 72.00 TB 72.00 TB +0.00 TB

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

Which has more real-world usable available space: RAID-Z2 or RAID 6?

This NAS planning scenario compares both modes at fixed drive sizes so you can see usable capacity differences before buying disks.

Does RAID-Z2 rebuild faster than RAID 6?

Rebuild behavior depends on array width, disk size, and workload pressure. This page focuses on capacity and tolerance; benchmark your actual platform before final choice.

Does this comparison include filesystem reserve?

Yes. The comparison table applies a 10% reserve baseline to reflect realistic operating headroom in NAS and homelab environments.

How should I pick between RAID-Z2 and RAID 6?

Choose based on your risk tolerance, rebuild window, and performance profile. Higher parity usually lowers capacity but improves resilience.