Say you’re a small company and you have a network with only one domain controller. Your domain controller goes down and you discover your backup is corrupted. Will the following recovery procedure work? Re-install Windows Server 2003 on your machine giving it the same computer name and IP address as your old domain controller had, then promote your server to a domain controller giving it the same domain name as you used previously. Will users then be able to use their client computers to log onto the domain as before? No! You’ll have to rejoin all your client computers and member servers to the new domain, and reconfigure permissions on all your shared resources on any file servers, print servers, and so on that may be on your network.
Moral of the story? Either invest in a second domain controller for fault tolerance, or invest in more reliable backup hardware/software/media.
Mitch Tulloch was lead author for the Windows Vista Resource Kit from Microsoft Press, which is THE book for IT pros who want to deploy, maintain and support Windows Vista in mid- and large-sized network environments. For more information see www.mtit.com.