You can restore a domain controller by restoring the System State data from backup media. There are two general methods for restoring Active Directory from backup media i.e non authoritative and authoritative. Non authoritative restore means that when a domain controller is restored from backup media, the restored data is updated through normal replication. Each restored directory partition is updated with that of its replication partners. Authoritative restore means that after Active Directory is restored non authoritatively from a backup medium the restored DC takes precedence over any other domain controllers in the domain. If restored DC has old data it will replicate to all its replication partner DCs in case we do authoritative restore.
You can restore a domain controller from backup media only while Active Directory is offline. You can take Active Directory offline by placing the domain controller in Directory Services Restore Mode. To recover the system state using Windows Server Backup, you must be a member of the Backup Operators or Administrators group.
To put a domain controller into Directory Services Restore Mode
- Restart the domain controller.
- When you are asked to choose which operating system you want to start, press F8.
- Select Directory Services Restore Mode , and then press ENTER.
When you restart the computer in Directory Services Restore Mode, you must log on to the local computer as an Administrator. The DSRM password would be the one we defined while promoting the domain controller in the past.
o recover the system state using the Windows Server Backup user interface
- From the Start menu, click Administrative Tools, and then click Windows Server Backup.
- In the Actions pane of the snap-in default page, under Windows Server Backup, click Recover. This opens the Recovery Wizard.
- On the Getting Started page, do one of the following and then click Next:
- Click this server.
- Click another server. On the Specify Location Type page, do one of the following and then click Next:
- Click Local drives. On the Select Backup Location page, select the volume or drive that contains the backup from the drop-down list. On Select Server, select the server whose data you want to recover.
- Click Remote shared folder. On the Specify Remote Folder page, type the path to the folder that contains the backup. In the folder, the backup should be stored at \\<RemoteSharedFolder>\WindowsImageBackup\<ComputerName>\<YourBackup>.
- On the Select Backup Date page, select the date from the calendar and the time from the drop-down list of the backup that you want to restore from, and then click Next.
- On the Select Recovery Type page, click System state, and then click Next.
- On the Select Location for System State Recovery page, do one of the following, and then click Next:
- Click Original location.
- Click Alternate location. Then, type the path to the location, or click Browse to select it.
- On the Confirmation page, review the details, and then click Recover to restore the listed items.
- On the Recovery Progress page, you can view the status of the recovery operation and whether or not it was successfully completed. After the operation completes, you must restart your computer.
You can also perform this task remotely for another server using the Connect To Another Computer option in the Windows Server Backup Microsoft Management Console (MMC) snap-in.