You don't _need_ it but it does make some tings easier.
You need the HP software if you want to have the SANs mirrored at a
level "underneath" the NOS, ei.e. at the hardware level. It will also
facilitate the scripting that will automagically swap the pool/volume
from a downed SAN to the up SAN.
This could be useful when you're in a disaster-type situation. I
generally recommend it's better to pay a little extra for stuff that
will make your life a lot easier and less error-prone when the stuff
starts hitting the fan.
--
Cheers!
Richard Beels
~ Network Consultant
~ Sysop, Novell Support Connection
~ MCNE, CNE*, CNA*, CNS*, N*LS