Virtualizing Windows Server Domain Controllers

Miguel Angel Perez Muñoz
The purpose of this article is make a little review on How to virtualize a domain controller (DC) from physical to virtual and has no or minimal impact on your network using Vmware environment.

I recommend checking the health of your DC and make a checklist of every service running on machine. Then, copy and do a final checks before put on working environment.

In this example (sorry for the lack of pictures, my OSes are in Spanish) I will convert one fully functional Windows 2003 standard DC with DNS and DHCP server to virtual. The steps may be similar to those for earlier versions:

1- Check your server.
This steps ensure server and services to be copied are in good condition. In my opinion it is nonsense to copy anything that isn't already working properly and troubleshooting could be more complex in such a case as well. This article is focused on AD services because it is the object of article, but may require additional steps if you are running any other services:

Take your IP address and make a full backup.
Download and setup Windows 2003 resource tools. Can be done from this link:
Run dcdiag and check output. Usually all test must show as passed.
Resolve any error before continue, this guide would help you: Rerun dcdiag and check again.
Check replications with repadmin /showreps. This test replication with other DC´s. Replication must be functional to all DC´s according to your topology, by default between all DC´s.
Repair any failure before continue, this guide may help you:
Move your FSMO roles to other server is highly recommended:
Check and repair another service running on this server. Event viewer would provide some additional information.

If your server passes these checks and your backup is complete, then go on to...

2- Cloning
Ensure your are running this from computer or server with an UPS and disable any kind of energy savings (enabled on desktops by default).
Login your DC server and run services console. Stop your DHCP server service (this ensure your server do not any lease during cloning that could not be on destination virtual server). All services like databases or file shares must be stopped during this process.
Start vmware converter ( on Windows 2008/2012/Win 7 must be run as administrator) and select convert machine.
In the dropdown menu select powered on machine, search your machine and provided required credentials. These credentials must have administrator privileges
Select your destination machine (Vmware hypervisor server) and provide required credentials to login.
Input a machine name.
Ensure you have got enough free space, unless process could not be complete.
Before continue have to review some options: On LAN section disable "connect at power on". Go to advanced, post-conversion section and mark "power off source machine", "power on destination machine", "install vmware tools" and remove mark from "Reconfigure destination virtual machine".
Submit job and wait until process start. When reaches 1% go to your DC and run "net stop netlogon" on command prompt. This stop your logon service and void any kind of communication between DC and other machines. You must to wait until process start, other way causes converter can not login and process fail.

3- Booting virtual server
Ensure your source server has power off, sometimes shutdown fail.
Login through vShpere client on your new virtual DC. Automatically setup of vmware tools finishes and now have a new ethernet connection without IP. Reboot is required.
After reboot (may be very slow because have not got LAN) put your physical IP address on virtual ethernet adapter. May have warning tip because old ethernet adapter has same IP, can be safely ignored.
Edit your virtual machine, LAN section and mark "connect at power on". Reboot.

4- Final checks
Run dcdiag on virtual server and check output. All test must passed.
Check replications with repadmin /showreps.
Check another service running on this server.

Now your server is virtual and fully functional, remember make to backups frequently.
Miguel Angel Perez Muñoz

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