@Dashrender said in RAID 10, 20 Disks, How Many Hot Spares:

So is it done? Does Matt understand and agree to the point that Scott was making?

Yes I believe so.

TL;DR attempt #1 #2 #3 #4 (counting edits)

RAID10 does not need hot spares

If you have spare slots you'd be better served by a larger array with more IOPS

The corner case (the one raised by the op's question?) is would hot spares reduce the risk of array failure. The answer is 100% absolutely yes it will reduce the risk of failure.

The disagreement (I think..?) was if that's necessary. We agreed that it isn't necessary to have any hot spares for RAID10 unless there's mitigating factors (examples: remote COLO with horrific access issues, extremely risk averse use case).