Probability of a RAID 6 (double parity) failure, leading to total loss of all data.
Drives: 23 (2 parity drives) Total capacity: 12TB MTTR: 16 hours (rebuild time) Hot spares: infinite
Capacity: 585GB MTBF: 43800 hours URE rate: 1e+16
Annual probability that 3 drives fail within the MTTR window (thereby destroying all data):
Annual probability that 2 drives fail (3.851%), combined with an Unrecoverable Read Error (URE) during the rebuild (0.011%):