HI
more info please! Broadly specking the guest is unaware its a virtual machine so there is no conecpt of getting the physical host that a vm is running on from within a vm.
Of course you could write something with the SDK or the vi perl toolkit, install it in a vm to lookup the guests own name and then query VC to try to determine which esx server that vm is running on. There are any number of gotchas with this (for example, it relies on the VM name registered in VC being the same or close to the hostname within the guest)
It all sounds a bit odd to be honest and I'm not sure I can think why you'd want to (apart from some vague ideas about security exploits....)
