Bing:  How long until you plan to upgrade the remaining switches? A week or so?  In general I would approve of this unless you plan to immediately begin using a "new feature" specific to 5.0.1. Looking through the release notes, I don't think that's a concern here.  I've attached the release notes so you can check to see if anything pertains to your specific configuration. I don't think there will be a problem specific to the servers or arrays though.  Thanks, Jim
I have 2 -  MDS 9513's each in it's own fabric and  2 - MDS 9509 each in it's own fabric.  All switches running 4.1.(3a) I have hosts connected to each of the 9513 fabrics and the same for the 9509 fabrics. The hosts are mostly Windows servers 2003 and 2008 with some ESX 3.5 servers.  All systems are running some version of Multipathing and Navisphere Agents. The Clariion arrays are CX4-960's (one of which hosts NAS disks), CX3-40f (NS40) and CX3-80 which is an integrated NSG80   The question is can I upgrade 1 of the 9513's & 1 of the 9509's  to 5.01 without having issues on the hosts or with the Clariion arrays.  Thanks, Bing
Rolling Cisco Switch Upgrade