Protecting a Non-Domain Server

1) Map the C: drive of the DPM server at the non-domain server. Provide the domain admin username and password when prompted.

net use Z: \\DPMServer\C$


2) From elevated command prompt, at Z:\Program Files\Microsoft System Center 2012 R2\DPM\DPM\ProtectionAgents\RA\4.2.1205.0\amd64,
run DPMAgentInstaller_x64.exe.
Accept the license and proceed.


3) Now from C:\Program Files\Microsoft Data Protection Manager\DPM\bin,
run:
.\SetDpmServer -dpmServerName DPM_FQDN -isNonDomainServer -userName New_User        -productionServerDnsSuffix Domain_Name

Where, DPM_FQDN:  DPM Server's FQDN
             New_User : Provide a new username that will be used by the DPM server as well.


4) Now from DPM Server's Agent Installation wizard, select Attach agent -> Computer in a Workgroup or untrusted domain.


5) Enter the non-domain server name (FQDN), the username created in step 3 and the password for the user.


6) Attach the agent.

Now you are ready to protect the server.

Note: Remember to change the DNS domain of the non-AD domain server to the one same as of DPM server.