Windows Server 2012 – Virtual Domain Controller Snapshot Restore

Almost every company is using virtual machines today.

The advantages:

• VMs can be drawn up easily.
• Before important changes you can make snapshots.
• In case something should go wrong, you can restore the last snapshot.

Since Windows Server 2012 domain controllers can also be restored via snapshot using an appropriate hypervisor.

Among other things Microsoft introduced the Generation ID with Windows Server 2012. This makes a restore from of a virtual domain controller snapshot possible. With Generation ID you can check whether a domain controller was restored via snapshot or not. The ID is saved within the attribute msDS-GenerationID of the computer object in the Active Directory. During every restart of the domain controller it is checked if the ID has been changed. The ID changes when a snapshot is restored from a backup.

Should the ID have actually changed the Unique Sequence Number (USN) among others is reset and a „non-authoritative SYSVOL”-synchronization initiated. Already assigned UNS’s will not be reassigned. The replication among the domain controllers will also not be disturbed.

USN-Rollbacks should thus belong to the past. However, it has to be checked if the used hypervisor supports this function.