We've got two Hyper-V hosts running multiple VMs (all flavors of Windows Servers). One of the VMs is running MS Data Protection Manager 2010, which runs beautifully (most of the time) and is connected to a separate NAS via iSCSI for the DPM storage.

I noticed when I installed the DPM agent on the Hyper-V hosts, it enumerates the VMs in the DPM Protection listing. I don't want to burn through my storage space too fast with duplicate protection, so I was wondering:

Is it recommended to back up VMs through the host, or is it better to install the DPM agent on each VM and backup as I would any other machine?

It would seem as though most people (currently including me) do it the second way, but is there any advantage to including the entries under HyperV (Backup using Child Partition Snapshop)?