There have been quite a lot of discussions lately on the VMware forums about topics related to exposing physical hardware layouts to virtual environments. Specifically I am referring to things like: RDM's, NPIV's and Virtualization of I/O. There might be other stuff being discussed but these three are those about which I'd like to throw my two cents.I am sure most of the readers know what an RDM is: Raw Disk Mapping is a method by which you expose to a virtual machine an entire SAN LUN instead of letting ESX create a VMFS volume.