RAID stripe size (was: 5.1 RAID5 write performance)

[Edgar Fuß <ef%math.uni-bonn.de@localhost>]

> Ah, yes, the old 
> rmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmwrmw
>  cycle.  Gets me every time.
OK, I've fixed that (before doing the tests I reported the last two days).

So, what's the advantage of a larger sectPerSU?
It appears to me that the raidctl manpage should note that
-- the stripe size should match fsbsize
-- partitions within the RAID should be aligned to the stripe size.