Re: swap-on-raidframe vs raidctl -P

[der Mouse <mouse%Rodents.Montreal.QC.CA@localhost>]

>> One would be a way to configure raidframe for uses (like swap) that
>> don't care about data preservation when the partition is not in use;
>> parity rewrite at boot would be dummied out for such partitions.
> Consider a RAID 5 set, used for swap, where there is a stripe with
> bad parity.  Let the blocks of that stripe be A, B, and P.  A "small
> write" to A will read P, compute P', and write out A' and P'.

How can it compute P' without having B on hand?  I must be missing
something.

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