Some administrators back up only the data portions of their servers. Other administrators back up everything; that way, in the event of a catastrophic server failure, they could simply restore the backup tape and have the server ready to go with no additional configuration. If you like the idea of backing up the entire server, and you upgraded from Windows NT to Windows 2000, your backup may not be as comprehensive as you had hoped.
The System StateIf you look at the Windows 2000 backup program, you'll notice a System State item in the list of hard drives. The System State includes the system's Registry, class registration database, and boot files. If you're backing up a certificate server, the System State also includes a copy of the certificate database. In addition, if you're backing up a domain controller, the System State includes the Active Directory and the SYSVOL folder. The System State elements of Windows 2000 can't be backed up as part of a file-level backup of the hard drives. If you upgraded from Windows NT to Windows 2000 and didn't upgrade your backup software in the process, then your backup software won't even have an option to back up this important information. You may wonder why these items are listed together as the System State, instead of being listing individually--after all, other versions of Windows let you select a check box if you want to back up the Registry. The items aren't listed individually because most of the System State components are highly dependent on one another.
Restoring the System StateBecause the System State components are so dependent on each other, you can't restore them individually--you can only restore them collectively. (The one exception occurs if you're restoring the System State to an alternate location. In this case, only the Registry, SYSVOL folder, and boot files will be restored.) Restoring the System State is a bit tricky. The restore process needs to overwrite critical operating system components (such as the Registry) that are in use. There's also the problem of replication in environments with multiple domain controllers. If you restore the Active Directory, other domain controllers will see that the sequence number for the restored data is out of sync. Therefore, they will attempt to overwrite the restored information with their own information.
To get around these problems, you must boot the system into Directory Services Restore Mode. Once you've done so, you must perform an authoritative restore. When you do, any Active Directory information you restore will take precedence over existing Active Directory information, and will therefore be replicated to the other domain controllers. //
Brien M. Posey is an MCSE who works as a freelance writer. His past experience includes working as the Director of Information Systems for a national chain of health care facilities and as a network engineer for the Department of Defense. Because of the extremely high volume of e-mail that Brien receives, it's impossible for him to respond to every message, although he does read them all.