I'm preparing for an upgrade of an ESXi 3.5 server to ESXi 4.0. Before the upgrade I'm going to disconnect datastores that reside on a SAN. I've got two questions:
1. When shall I disconnect SAN's iSCSI cables? Shall I shut down the host or put it into the maintenance mode or power down the guest machines and remove the cables?
2. I'm going to use vSphere host upgrade utility. Is it worth backing up the host config using vicfg-cfgbackup or it should be preserved duirng the upgrade?