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EU 10x 20TB RAID 6 NAS Calculator

Estimate usable TB, parity, and fault tolerance for EU homelab buyers using 10x 20TB in RAID 6.

Capacity Snapshot

Raw Capacity

200.00 TB

Usable Capacity

144.00 TB

Fault Tolerance

2 drives

Efficiency

80.0%

Safer for larger arrays with dual parity, at the cost of one extra parity disk. This scenario applies a 10% filesystem reserve.

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Alternative Mode Comparison

Mode Usable Tolerance Efficiency
RAID 5 162.00 TB 1 drive 90.0%
RAID 6 144.00 TB 2 drives 80.0%
RAID 10 90.00 TB 1 drive per mirror pair* 50.0%
RAID-Z1 162.00 TB 1 drive 90.0%
RAID-Z2 144.00 TB 2 drives 80.0%

EU Buyer Context

EU deployments often place additional emphasis on energy efficiency and predictable lifecycle upgrades, especially for always-on NAS fleets.

Brand / Region Glossary

Lifecycle Planning

Capacity and reliability strategy across multiple hardware refresh cycles.

Operational Headroom

Intentional free-space margin to protect performance and snapshot behavior.

NAS Cluster Guides

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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.

Is RAID 6 still practical with 20TB drives?

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

How many disk failures can RAID 6 tolerate in this setup?

This setup can tolerate 2 drives. Real-world survivability depends on mirror placement, rebuild stress, and drive health.

How much usable storage does 10x 20TB RAID 6 provide?

For EU homelab buyers, this NAS planning scenario estimates 144.00 TB usable after a 10% reserve from 200.00 TB raw.