very strange situation today. I performed a single disk svMotion on my vCenter VM which also had 4 mapped raw LUNs. However, after a reboot, the VM never came back on line saying that it cannot find the boot device.
after much tinkering around, I performed the following to get my vCenter back:
Attached Server 2012 ISO to the VM.
From the command prompt
select disk 0
select partition 2 (this will depend on your windows installation, if you remember it)
then the following commands