In the first link, there is an additional information note ...
VMware does not recommend to take a snapshot of the virtual machine running as a Domain Controller. In Windows Server 2012, there are changes to support creating a snapshot. For more information, see the Microsoft TechNet article, Introduction to Active Directory Domain Services (AD DS) Virtualization (Level 100). If the virtual machine is running a Windows Domain Controller, then snapshots are not supported by Microsoft. For more information, see Virtualizing a Windows Active Directory Domain Infrastructure white paper.
The second link states ...
There is a link to a white paper with the following note:
Note that Microsoft does not support using snapshots or disk
imaging of any domain controller. You must perform system
state data backups to protect the Active Directory database.
Snapshots can potentially corrupt the Active Directory database
without even committing or reverting back to the snapshot.
Another quote from link 2:
Since VMware policies actually takes snapshots of the VMs for backup (via the vStorage API), all of the above should paint a pretty clear picture that backing up AD/DC this way is not recommended or supported by anyone, including NetBackup.
NetBackup's only documented (i.e., supported) way of backing up AD/DC is via the System State or Shadow Copy Components directives.