To DC or not to DC that is the question.....

Urban Legend..."Did you know that it is impossible to have additional Domain Controllers in a Small Business Server Domain?"

This is in fact a myth as long as a few conditions are met. 

  1. The SBS 2003 computer must be a domain controller that is installed on the root of the domain.
  2. The SBS 2003 computer must hold all the Flexible Single Master Operation (FSMO) roles.
  3. The SBS 2003 computer must be a global catalog server and must be the licensing server.
  4. There must not be any existing domain trusts or child domains.
  5. Only one SBS server can exist on the domain. If SBS 2003 is installed, no other SBS 2003 or 2000 server can be installed on the same domain 

What The heck is a FSMO role... see https://support.microsoft.com/kb/324801 for a brief description.  

So why would I need an additional Domain Controller anyway? Along with the benefits an additional domain controller can add to a network by it's nature, it also has a copy of your Active Directory data.

Here's the scenario: I have an SBS server, 1 additional domain controller and 35 testy users.... ;)

A storm is rolling across the plains... Lightening strikes the local electrical company, something happens with the local backup power supply for the network and all the servers come crashing down. With fingers crossed you re-start all of the network boxes. Client boxes restart fine......including the V.P. that always wants to keep 10gb of email - :)! You walk back into the server room - to find the additional DC has recovered fine, but after several calls you find that the motherboard on the SBS server is going to need to be replaced! 

Uhh-ooh new hardware....yikes...now were looking at downtime but little do I realize that this is the least of my worries! How is new hardware going to react with my current set of backups for the SBS server? Am I going to have to reinstall the domain? Whats going to happen to all of the current desktop profiles for my 35 testy users? Is Exchange going to work? Are my backups any good? Can I restore the data? How long is this going to take?? Man i'm in trouble...........right? No not really, as long as you have valid back-up of your data, and an additional, current, functional, domain controller in your domain to help with you Active Directory information.  

Even though you have lost your SBS server, fortunately for you, you still have a current DC from you old domain. An existing domain controller = an existing domain. So how would I install an SBS server into an existing domain? Fortunately there is an article available "How to install Small Business Server into an existing Active Directory domain" https://support.microsoft.com/kb/884453/en-us . This article walks you through how to reinstall SBS on to new hardware, while still having the ability to work around the necessary boundries of SBS.

Second DC.........Just say yes!

>edwalt