I was wondering if I can get some feedback in regards to Virtualizing the Domain Controller.
I was told by some that Virtualizing ALL the DC's is not a good idea and that its best practice to have one PHYSICAL Domain Controller available just incase. Some say that virtualizing a DC and not have any PHYSICAL Domain Controller is not an issue as long as there is fault tolerance and the virtual hard drive file is accessible.
Some clients, do like to prefer to be able to "touch and stroke" their DCs.
see here also
What you must not do, if you use snapshots, for patch management, is rollback or Revert a DC using snapshots, but we think this is common sense, but Virtual Admins seem to forget this!