Hi, I have an HP MSA 2000i as SAN (iSCSI) and since I'm starting with SANs, I'm seeking for advice. We are currently using HP Proliant 380 G5 + MSA 70 (SAS, direct-attached storage) for our production servers. At first, I thought I'd be using the SAN only for non-critical operations, like temporary additional storage for disk-based backups and snapshots, so I planned on using my existing network equipement to connect the SAN. Now I'd like to use it as storage for some blade servers that I want to use for virtualisation, so reliability is more important. I'd just like to evaluate the risk, to make sure I plan correctly. The SAN is a dual controller, dual-port, with a mix of RAID10 and RAID 50 arrays, so this is pretty solid. However, if I'm using only one switch to connect the initiators to this SAN, is it more risky than relying on the non-redundant RAID controllers that are in my HP servers? If it is recommended that I use multipathing, I guess that means 2 switches, additionnal nics but also another interconnect in the blade enclosure? If you need more information, just let me know :). Thanks in advance, Ugo