In relation to my work I'm currently reading a book PostgreSQL 9.0 High Performance and there is a great quote about SAN/NAS/DAS: "SAN and NAS hardware is typically much more expensive than DAS, and easier to manage in complicated ways."

HP just published an advisory describing how to tune some parameters for Emulex, Qlogic and Brocade Fibre Channel HBAs: c02518189. It sounds like these are new, but these changes have been around for at least 6 months in all three vendors' HBAs. Emulex "Emulex driver version 2.42.002 or …