Recipe15.2.Promoting a Domain Controller from Media

Recipe 15.2. Promoting a Domain Controller from Media

This recipe requires that the server being promoted run Windows Server 2003.

Problem

You want to promote a new domain controller using a backup from another domain controller as the initial source of the directory contents (DIT) instead of replicating the entire DIT over the network.

Solution

Using a graphical user interface

You first need to back up the system state of an existing domain controller in the domain where the new server will go, by running the MS Backup utility found at Start
Once you have a good backup, you need to restore it to the new server, which can also be done using MS Backup. You should restore the files to an alternate location, not to their original location.
Next, run dcpromo with the /adv option from a command line or Start
After the dcpromo wizard starts, select Additional Domain Controller for an existing domain and click Next.
Under Copy Domain Information, select From these restored backup files, browse to the backup files you created in step 2, and click Next.
Enter credentials of a user who is part of the Domain Admins group in the domain you are promoting the domain controller into and click Next.
Choose the folders to store the Active Directory database and log files and click Next.
Choose the folder to store SYSVOL and click Next.
Enter a Restore Mode password and click Next.
Click Next to start the promotion.

Discussion

Being able to promote a domain controller using the system state backup of another domain controller is a new feature in Windows Server 2003. With Windows 2000, a new domain controller had to replicate the entire DIT over the network from an existing domain controller. For organizations that had either a really large Active Directory DIT file or very poor network connectivity to a remote site, replicating the full contents over the network presented challenges. Under these conditions, the promotion process could take a prohibitively long time to complete. Now with the dcpromo install from media option, the initial promotion process can be substantially quicker. After you've done the initial install from media (i.e., backup tape or CD/DVD), the domain controller replicates the changes since the backup was taken.

Be sure that the backup files you are using are much less than 60 days old. If you install a domain controller using backup files that are older than 60 days, you could get in trouble with zombie objects getting re-injected after being purged (due to the default 60-day tombstone lifetime).