Installing DPM 2010 Agents to a Cluster
When installing DPM 2010 agents to a server you intent to protect, you use the Protection Agent Installation Wizard to push out that agent. Installing the agent requires a reboot! This reboot is necessary to ensure that the protection agent is installed correctly.
So what happens when that server you intent to protect is a member of a cluster (MSCS)?
Firstly, it is important to point out that if you do selected a server in a cluster, then DPM 2010 will detect the additional servers in that cluster and you must install the agents on all nodes within the cluster to successfully protect the clustered data.
However, when it comes to a cluster, DPM will not restart a server that belongs to cluster. You have to manually restart the server in the cluster.

Patrick Lownds