I have a brand new VDP 5.1.1 setup and it is not backing up my Windows Domain controllers or my SQL Server virtual machines. How can I start diagnosing what is going on?
I would avoid backing up your DCs this way entirely, as it is completely unsupported by Microsoft. Just dump the system state to a share on a server that VDP backs up - then you will have a supported way to restore AD.
What version(s) of SQL are you running?
Various SQL Server 2005 and 2005. Just noticed that an Oracle server is failing to backup also.