Having installed several clusters and fully understanding and accepting the
NetWare partition:pool:volume 1:1:1 relationship I would like to understand
this latest fad of adding the LUN assignment into the relationship?!?

I've always assigned the amount of space required for a particular OS
cluster into a LUN and then masked that to the appropriate hosts, where it
is then split into partitions, etc.
What are the benefits for having multiple LUNs? Presumably you still have a
single RAID (5,10, whatever) group under it? Aren't you just putting more
stress on the storage controller(s) and logic they process? Can't the
storage processors/OS sometimes become a bottleneck?
What about expansion and metaluns?

Just looking for the reasoning, which I'm quite happy to accept if it makes
sense! ;-)