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> I chose raidz1. With only a handful of disks, the odds of two drives failing simultaneously is fairly low.

Is this how the math works? Does having more drives mean the individual drives themselves are more likely to fail? Is running 4 drives safer than 100?

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The number of parity drives is often fixed, so the odds of the number of failures being higher than the number of parity drives goes up as you increase drive count.

Depends on how you look at it I suppose. The lifespan of a singular disk is likely rather long, but put a dozen of them in the same place and you'll see a failure or two every few years.

Of course, we know that having a larger sample size and seeing more failures doesn't _actually_ mean that groups of disks are less reliable, but it could seem that way if you don't think too hard about it.

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