Handling template clones with VMs joined to a Windows Domain

 

When you join a Windows VM or physical machine to a Domain, a unique identifier or SID (that is generated in Windows during the machines initial boot) is used to uniquely identify the machine to the Domain.

However, the power of Virtualization ability to replicate and deploy copies of individual machines or entire networks can cause some challenges. For example, if you snapshot a Windows VM, and then redeploy another copy with the intention of adding both machines to the same Domain, you will get a "Duplicate SID" error.

***Keep in mind this error should only occur if you add a copy of a VM to an existing Configuration where an original copy of it already exists. If you are simply deploying a single copy of the machine into a unique Configuration, meaning there is no version of itself already there, then there shouldn't be any conflict.***

If your intent is to be able to deploy multiple copies of a Virtual Machine that will be running at the same time in the same Configuration, it is best practice to:

a) Get the Virtual Machine to the desired state, and snapshot it BEFORE adding it to the domain.

b) When you add a copy of the machine to the domain, make sure it has a different (ie, unique) Computer Name (hostname). As a result, you may want to select a generic name for your base machine, and be sure to change it when you deploy it, BEFORE powering it on. Once powered on, you can join the machine to your Corporate Domain.

c) If you have a machine that is already a member of a domain and you wish to deploy multiple copies of it, you should utilize Sysprep to clear the machine's SID. This process can be found at:
For Windows XP/2003: http://support.microsoft.com/kb/302577
For Windows Vista and 7: http://technet.microsoft.com/en-us/library/cc721940(WS.10).aspx

A few final thoughts on Sysprep:

The Sysprep process is known to cause the drivers associated with VM mouse cursor control to become non-functional (part of the sysprep process is that it reinstalls the default drivers, which are installed over the VMware Tools drivers). As a result, to regain cursor control, you will need to re-install VMware Tools on your VM after Sysprep completes. This can be a tricky process, as you won't have cursor control (all inputs will need to be provided with the tab, spacebar, arrow, and enter keys on your keyboard). Please see the following KB article for more information on updating/installing Tools:
How to install and upgrade VMware Tools