> From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss-
> boun...@opensolaris.org] On Behalf Of Jim Klimov
> I tend to agree that parity calculations likely
> are faster (even if not all parities are simple XORs - that would
> be silly for double- or triple-parity sets which may use different
> algos just to be sure).
Even though parity calculation is faster than fletcher, which is faster than
sha256, it's all irrelevant, except in the hugest of file servers. Go write to
disk or read from disk as fast as you can, and see how much CPU you use. Even
on moderate fileservers that I've done this on (a dozen disks in parallel) the
cpu load is negligible.
If you ever get up to a scale where the cpu load becomes significant, you solve
it by adding more cpu's. There is a limit somewhere, but it's huge.
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