It is currently not possible to use the Repair Wizard to bring up a Domain Controller on identical hardware using a backup from a DC which is offline due to hardware failure. Despite being on identical hardware the operating system will contain many unique parameters. Those parameters are defined during the installation of the Operating System. Repair wizard will replace the current DIT file (with transaction logs) and the registry, however replacing the registry taken from another OS (even with similar hardware) may lead to OS instability or it may not function at all. For this reason, we do not recommend using the Repair Wizard in this situation. It is better to use Bare Metal Recovery in this case.
Start the Repair Wizard and follow the instructions in the wizard.
The Repair Wizard enables the recovery of the whole Active Directory database on a domain controller by applying a backup that was created for that domain controller.
You can use the complete offline restore to restore the entire Active Directory database from backup media without reinstalling the operating system or reconfiguring the domain controller. The restore can be performed on any domain controller that can be accessed remotely. By default, this operation restores all directory objects on the target domain controller non-authoritatively. This means that the restored data is then updated via normal replication. A non-authoritative restore is typically used to restore a domain controller that has completely failed due to hardware or software problems.
A backup created for a given domain controller cannot be used to restore the Active Directory database to other domain controllers.
A complete offline restore also allows you to mark individual objects for authoritative restore. However, given that the granular online restore process provides the same functionality with much less effort and overhead, it is the recommended method for restoring individual objects to Active Directory.
During the final stage of a complete offline restore, the recovered domain controller is restarted in normal operational mode. Then, Active Directory replication updates the domain controller with all changes not overridden by the authoritative restore. It is important to note that until the replication update has completed, some of the directory object data held on the recovered domain controller may be obsolete. Therefore, execution of a complete offline restore may result in additional downtime due to replication delays.
There is one other consideration to make when performing a complete offline restore. Since you cannot use the backup from the other domain controller for the restore, the restored domain controller may lose information about the directory updates that were made after it was backed up. For example, suppose that some directory objects were added or modified on the domain controller after the backup was created, but the new objects or modifications were not yet replicated to other domain controllers. In this case, when the domain controller is restored, the new objects or modifications will be lost, because they were never replicated to other domain controllers, and therefore cannot be applied to the restored domain controller.
The Repair Wizard lets you select the target domain controller and the Active Directory backup for that domain controller, and then guides you through the operation.
You can select the domain controller where you want to restore Active Directory and then start the Repair Wizard by clicking Repair on the Action menu. As a result, the wizard only displays the backups created for that domain controller.
In the Repair Wizard, you can use backups created by applications that store backups in Microsoft Tape Format (MTF), such as Windows Backup or Veritas Backup Exec. To use a backup, on the Computer and Backup Selection window, click Register, and then register the backup using the Register Backup File or Register Backups in Folder item. Note that snapshot backups are not supported by the Repair Wizard. You can restore Active Directory data from such backups using the Online Restore Wizard and Group Policy Restore Wizard. The Extract Wizard also supports snapshot backups.
Active Directory restoration requires that the domain controller be restarted in Directory Services Restore Mode. At your discretion, the wizard restarts the target computer automatically or allows you to restart the target computer manually.
You will need to log on to the target computer as an Administrator after the Repair Wizard restarts it in Directory Services Restore Mode. To do this, you must use an account whose user name and password are stored in the local security account database, known as the Security Accounts Manager (SAM). You cannot use the user name and password of the Active Directory administrator.
Restart the computer and press F8 when you are prompted to do so.
On the menu, choose Directory Services Restore Mode and then press ENTER.
If you have multiple systems installed on the computer, choose the Windows installation you are recovering, and then press ENTER. You must choose the Windows installation that was running when you launched the Repair Wizard.
After the target domain controller is restarted in Directory Services Restore Mode, the wizard restores the Active Directory database from the backup.
Optionally, the wizard allows you to mark individual objects, a subtree, or the entire directory as authoritatively restored. To mark AD objects, subtree, or the entire AD database as authoritative, Recovery Manager for Active Directory uses the capabilities provided by the Ntdsutil.exe tool supplied with Microsoft Windows. However, this tool included in Windows Server 2008 or higher does not support marking the entire AD database as authoritative.
The authoritatively restored objects replace existing copies of those objects on all domain controllers and prevail for the entire domain.
After the Active Directory database is restored, the target domain controller must be restarted in normal operational mode. At your discretion, the Repair Wizard restarts the target computer automatically or allows you to restart the target computer manually. The restore operation is not completed until the target domain controller is restarted in normal operational mode.
This section provides important information you should consider when recovering Active Directory with the Repair Wizard.
The wizard allows you to restore Active Directory information on a domain controller by restoring its components from an Active Directory backup. This restores the entire Active Directory database along with the other Active Directory components on which Active Directory depends—SYSVOL and Registry.
The wizard offers the following two options for restoring Active Directory:
In this section: