On 20:12, Goswin von Brederlow wrote: > I'm wondering why the kernel requires a raid6 to have at least 4 > disks (of which at most 2 can be missing). Why not 3 disks? Yes, this limitation looks a bit arbitrary. I can not see any reason why raid6 requires at least four disks. Probably it even works without any significant changes if some of the checks are being relaxed. > Now for the raid6 case. With only 1 data disk and 2 parity disks all 3 > disks should end up with identical data on them. In effect this should > be a 3 disk raid1, a cpu intensive one. In fact, it wouldn't be much more CPU intensive than raid5 because the math to "calculate" the Q parity would obviously not involve any GF multiplications at all. > So back to my original question: Why does the kernel require 4 disks > for a raid6 instead of allowing 3? Dunno. Maybe Dan, Neil or HPA can tell the reason for imposing this limitation. Andre -- The only person who always got his work done by Friday was Robinson Crusoe
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