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APAC 4x 12TB RAID 10 NAS Calculator

Estimate usable TB, parity, and fault tolerance for APAC homelab buyers using 4x 12TB in RAID 10.

Capacity Snapshot

Raw Capacity

48.00 TB

Usable Capacity

21.60 TB

Fault Tolerance

1 drive per mirror pair*

Efficiency

50.0%

Excellent random I/O and rebuild behavior; capacity is typically 50% of raw. This scenario applies a 10% filesystem reserve.

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Alternative Mode Comparison

Mode Usable Tolerance Efficiency
RAID 5 32.40 TB 1 drive 75.0%
RAID 6 21.60 TB 2 drives 50.0%
RAID 10 21.60 TB 1 drive per mirror pair* 50.0%
RAID-Z1 32.40 TB 1 drive 75.0%
RAID-Z2 21.60 TB 2 drives 50.0%

APAC Buyer Context

APAC builders frequently compare availability windows and procurement variance, which makes robust fallback capacity and staged scaling useful in practice.

Brand / Region Glossary

Procurement Variance

Regional differences in disk availability and replacement lead times.

Spare Strategy

Policy of keeping spare disks available to reduce recovery delay risk.

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FAQ

Should I optimize this 4-drive plan for capacity or resiliency first?

For long-lived NAS pools, resiliency first is usually safer. Capacity can be expanded later, while a risky parity choice can force migration sooner.

Is RAID 10 still viable with 12TB drives?

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

Why include a 10% reserve when planning NAS available space?

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

How many disk failures can RAID 10 tolerate in this setup?

This setup can tolerate 1 drive per mirror pair*. Real-world survivability depends on mirror placement, rebuild stress, and drive health.