Just come across an issue during the VM-FEX proof of concept test with customer, I am using UCSM 2.0 and trying to configure VM-FEX with VMWare ESXi 5.0 and vCenter 5.0. We are using vCenter appliance 5.0, not installing the vCenter on Windows, for this test. The result is after the integration, all VM can't be powered up.
After a quick search and found this KB:
UCS Manager with VM-FEX does not support the vCenter Server Appliance in any available release.
After we build a new vCenter on Windows (not appliance), everything is working fine. :)