[acdha]

Oh, I’m sure they’re big on redundancy. I mentioned correlated failures, however, because that has multiple failure modes and the one I was thinking about is something like physical degradation: redundancy doesn’t help if all of your redundant nodes have a component which fails at roughly the same time. There’s a reason why storage admins learned to mix hard drive brands and manufacturing batches in RAID arrays, and that problem is much harder to solve in space.