Q. Should I install a System Center Data Protection Manager (DPM) 2007 agent on my guest OS virtual server?

There are also licensing considerations. If you deploy the DPM agent in the guest OSs, they each need an agent license.

This doesn't mean that protection at the virtual-server level is inconsistent. Virtual Server 2005 R2 SP1 has a recursive volume shadow copy service (VSS) writer, so when DPM 2007 asks the virtual server for a snapshot, the request is passed to all VM VSS writers, so you get a consistent data backup.

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