When backing up a Windows 2008 Domain Controller the below event may occur in the Application log:
Event ID: 40962
Details: "ASR Error: Fail to exclude disk#1. Reason: The disk contains a critical volume."
This error occurs when the Domain Controller has more than one hard drive which Recovery Manager considers to back up as well as the system drive.
This error can be safely ignored as it does not affect the backup or restore process. The product team is looking to resolve this error in an upcoming release of Recovery Manager for AD.
This error may not occur during a Windows native backup.