And these suggestions are even when I allow my DC to be my file server/DNS and also being my anti-virus and backup program host?

This is my first migration and Hyper-V setup. So, I've got a lot of lingering questions. Although many have told me virtualize, virtualize, virtualize, I almost feel more comfortable of sticking with having a physical DC/File Server.

I am about to virtualize our Domain Controller and I have some questions about it and the host/vm relationship.

First, what domain does the host get joined to, if at all? The old one until it is demoted or joined to the new, virtual one when it is promoted?

Next, are the recommended memory and CPU’s for a virtual DC? I’ve not found much in my usually reliable search methods.

Finally, since I used SBS 2003 for so long, I was used to my domain controller also being my file server, DNS, small needs web server and some print serving. Does that change how I need to set up the virtual DC then?