Nigel Griffiths (of IBM Power Systems Advanced Technology Support, Europe - but he is also known as Mr Nmon) gave a great presentation on Shared Storage Pools at Copenhagen. This was also presented in the excellent Webinar Series on Power Systems Virtualisation .
Here's a small extract on why you would use Shared Storage Pools:
In smaller companies, there is no SAN team. The server guys are the SAN guys. The idea of Shared Storage Pools is to allocated LUNs to the VIOS(s) and a single VIOS command can... [More]