If the root management server (RMS) in a System Center Operations Manager 2007 (SCOM 2007) implementation fails or becomes unavailable for some reason the entire SCOM system will fail. Well, not exactly. The managed agents will still collect performance and alert data and will either queue this data or forward it to its management server. The management servers will be unable to forward this information to the SQL database and administrators will be unable to launch either the Operations or web consoles, so it's as good as dead.
There are two ways to rectify this -- bring the RMS server back online or promote an existing SCOM management server to an RMS. Microsoft article, "How to Promote a Management Server to a Root Management Server Role in Operations Manager 2007" does a good job of explaining the steps required, so I won't go through them here. But what happens if you get the following error when promoting the new RMS?
The machine managementserver is a server for multiple management groups (not supported)!
This occurs when the registry contains extra "Parent Health Service" or "Send Priority" keys under the Server Management Groups key. Navigate to:
HKLM-Software-Microsoft-Microsoft Operations Manager-3.0-Server Management Groups
Under this key you should see a key that matches the name of your SCOM management group. There should not be any other keys at the same level as the management group name. Back them up and delete them. In the example below, backup and delete the "Send Priority" key and its subkeys.
Run the same ManagementServerConfigTool.exe PromoteRMS command and it should work now.