When making changes to Active Directory, like Schema updates, it is recommended to make a backup of AD. It is also recommended to perform these changes on an offline Domain Controller, perform your tests, and the only then replicate the changes to the remaining DCs. The topic of this article is about backing up AD.
NTDSutil provides a mechanism to perform backups on your domain controllers.
- Open an elevated command prompt and run NTDSutil.
- Run activate instance ntds to set the active instance to “ntds“.
- Type snapshot.
- Then Create.
For more details on NTDSutil: http://technet.microsoft.com/en-us/library/cc753343(v=WS.10).aspx