When restored non-authoritatively, the local copy of the SYSVOL that is held on the restored domain controller is updated with that of its replication partners. After the restored domain controller is restarted, it contacts its replication partners, compares SYSVOL information, and replicates the necessary changes, bringing its local copy of the SYSVOL up to date with the other domain controllers within the domain.
If the domain controller being recovered is the only functioning domain controller in the domain, a primary restore of the SYSVOL should be done. A primary restore builds a new replication service database by loading the data present under the SYSVOL onto the local domain controller. This method is the same as nonauthoritative except that the restored data is marked as the primary data.
Perform a primary restore only when all domain controllers in the domain are lost and you want to rebuild the domain from backup. Do not perform a primary restore if any other working domain controller in this domain is available. Use primary restore for the first domain controller, and then, later, use non-authoritative restore for all other domain controllers.
In this section:
With the Repair Wizard, you can perform an authoritative restore of Active Directory. The wizard allows you to mark the entire Active Directory database, a single subtree, or an individual object 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.
As a result, the wizard increments the version number of the attributes of all objects in the entire directory, all objects in the subtree, or the particular object to make it authoritative for the directory.
An authoritative restore can only be carried out on objects from the configuration and domain naming contexts. Authoritative restore of the schema-naming context is not supported.
When performing an authoritative restore of the Active Directory database, you should also perform an authoritative restore of the SYSVOL. With the Repair Wizard, the authoritative restore of the SYSVOL does not occur automatically. To do that, you should follow the procedure outlined in the next section.
By restoring the SYSVOL authoritatively, you specify that the restored copy of SYSVOL is authoritative for the domain. As a result, the replication service replicates the local SYSVOL out to the other domain controllers within the domain.
The bandwidth associated with such replication should be considered in case of an extensive use of large Group Policy objects and logon scripts in the domain.
Since the Online Restore Wizard and Group Policy Restore Wizard allow you to authoritatively restore directory data with minimal effort and overhead, we recommend you to use those wizards rather than the Repair Wizard when you need to recover/undelete individual Active Directory objects and Group Policy objects.