Change the Primary Management Server
We have had a few customers trying to "Change the Primary Management Server" of an agent (on the fly) unsuccessfully. This is done in the Admin pane of the UI (under agent managed, right click on the agent select Change Primary Management Server.
Once you have changed the Primary Management server, you will see your agent go Grey and no longer report back in to SCOM. In the Evt log you will see
Event Type: Error
Event Source: OpsMgr Connector
Event Category: None
Event ID: 20070
Date: 8/26/2008
Time: 5:53:19 PM
User: N/A
Computer: servername
Description:
The OpsMgr Connector connected to servername, but the connection was closed immediately after authentication occured. The most likely cause of this error is that the agent is not authorized to communicate with the server, or the server has not received configuration. Check the event log on the server for the presence of 20000 events, indicating that agents which are not approved are attempting to connect.
For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
The heart of the problem is the Gateway receives the new Configuration before the Agent you are trying to change does. Thus the old Gateway rejects the agent and never pushes the new configuration to said agent. Since the agent can't get the configuration from the old Gateway, and doesn't know to look to the new Gateway it simply drops from being monitored, Also the RMS will continue to hold the current configuration information so the agent never fails over (even if you manually change the configuration locally on the agent).
The fix to this problem is fairly straight forward. You have to configure Agent failover in the admin console (after running MOMADmin). Once you configure Agent Failover (again in the admin console, in the properties of each Management Server or Gateway) with the new gateway or management server you want to failover to you can use the "Change Primary Management Server" feature with in the GUI.
Read the complete post at http://david-stclair.spaces.live.com/Blog/cns!112A71B19678F08D!238.entry