RAID rebuild failure chance calculator.

This calculator determines the chance of a RAID rebuild failing due to an unrecoverable read error. The calculator makes a number of assumptions.

Other types of drive errors and failures are not considered as part of this calculator.

Type

RAID 5 RAID 6

Drive Size (GB)

500 GB 750 GB 1 TB 1.5 TB 2 TB 3 TB 4 TB 5 TB 6 TB 8 TB 10 TB 12 TB

Number of Drives

3 4 5 6 7 8 9 10 11 12 14 15 16 17 18 19 20

Unrecoverable read error rate

10 ^ 9 10 ^ 10 10 ^ 11 10 ^ 12 10 ^ 13 10 ^ 14 10 ^ 15 10 ^ 16 10 ^ 17

Errorless rebuild success chance: