How to Verify VMWare ESX Fibre Channel Configurations with Multipathing I/O (MPIO)

In ESX 3.5
1.Determine the available and active paths using the esxcfg-mpath program. The following output will provide the host initiator WWPN to storage controller WWPN mapping.
2.From the storage controller that is hosting the LUN, the command fcp show adapters may be used to display WWPNs of the FCP target ports. This output may be used to determine if the Active path is using one of the FCP target ports of the storage controller.
3.From the ESX host, use the command, excfg-hbadevs, to list the HBA devices. Note that the HBA name includes everything up to the first ":".
4.Rescan all of the HBAs using the esxcfg-rescan command. This will need to be done for each HBA attached to the ESX host.
5.Use the esxcfg-mpath command to change the host to use a primary path for the LUN. [root@esx-rtp]# esxcfg-mpath -p fixed --preferred -L vmhba2:0:1 --path=vmhba1:1:1

vSphere has changed the command structure, use esxcli command to list and manage the path or use vCenter manage path interface.