Reference Checklists provided on TechNet: http://technet.microsoft.com/en-us/library/hh241301

Reference How to Move Agents to a Secondary Management Server (Operations Manager Upgrade): http://technet.microsoft.com/en-us/library/hh241298

IMPORTANT: You must be running at least System Center Operations Manager 2007 R2 CU4 to perform the upgrade to 2012

If you are unable to Change the Primary Management Server from the Operations Console by right-clicking the Agent, then selecting another MS, follow the procedure outlined below:

Procedures for Server Core:

  1. Logon to the Server Core Computer using Remote Desktop (RDP)
  2. If you dont see a command prompt, hit Ctrl+Alt+End to open the Windows Security Dialog
  3. At the Security Dialog, select Start Task Manager
  4. Go to the File Menu, click ‘New Task (Run…)’
  5. Enter cmd.exe in the Open field, hit Enter
  6. To open Regedit, enter regedit.exe, hit Enter
  7. Navigate to the following Registry key
    1. HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall
  8. Expand the Uninstall Folder then look for the GUID that matches the installation by reviewing the details and highlighting each GUID folder value
  9. When you find the Uninstall folder that matches the Operations Manager Agent Install, Double click the ‘Uninstall String’, and copy the Value Data.
  10. Paste the Uninstall String into the command prompt window, then press Enter.
  11. You will see the Welcome window for the Agent Setup Wizard, click Next.
  12. You will see the Program Maintenance Window, click Modify, click Next.
  13. At the Manage Agent Management Groups Window, click ‘Modify Mangement Group’, and select the management group to modify if there is more than one, click Next. 
    1. You will have to repeat this process for all Management Groups.
  14. At the Management Group Configuration Window, ensure ‘Specify Management Group information’ is selected, click Next.
  15. Within the Management Server Field, enter the proper FQDN (servername.domain.com), for the Secondary Management Server, click Next.
  16. Click Next at the Summary Window, then Click Install.
  17. Within the Command  Prompt you opened earlier, stop the healthservice by using ‘Net Stop’ command below, hit Enter.
    1. net stop healthservice
  18. Wait for the HealthService to Stop.
  19. Within the Command Prompt Window, start the healthservice by using ‘Net Start’ command below, hit Enter.
    1. net start healthservice
  20. Wait for the HealthService to Start.

  21. Ensure the Agent displays properly (give it a few minutes), by opening the Operations Console on a computer with it installed, and go to Administration>Agent Managed.  Ensure the Server Core computer is healthy.

Procedures for Windows Full OS:

 

  1. Open Programs and Features or Add\Remove Programs from the Control Panel
  2. Right Click the System Center Operations Manager Agent, click Change
    1. For Operations Manager 2012 Agents ONLY – go to the Operations Manager Agent within the Control Panel root, and change the Management Server to the proper FQDN of the Secondary Management Server.
  3. You will see the Welcome window for the Agent Setup Wizard, click Next.
  4. You will see the Program Maintenance Window, click Modify, click Next.
  5. At the Manage Agent Management Groups Window, click ‘Modify Mangement Group’, and select the management group to modify if there is more than one, click Next.
  6. You will have to repeat this process for all Management Groups.
  7. At the Management Group Configuration Window, ensure ‘Specify Management Group information’ is selected, click Next.
  8. Within the Management Server Field, enter the proper FQDN (servername.domain.com), for the Secondary Management Server, click Next.
  9. Click Next at the Summary Window, then Click Install.
  10. Within a Command prompt, stop the healthservice by using ‘Net Stop’ command below, hit Enter.
    1. net stop healthservice
  11. Wait for the HealthService to Stop.
  12. Within the Command Prompt Window, start the healthservice by using ‘Net Start’ command below, hit Enter.
    1. net start healthservice
  13. Wait for the HealthService to Start.
  14. Ensure the Agent displays properly (give it a few minutes), by opening the Operations Console on a computer with it installed, and go to Administration>Agent Managed. Ensure the Server Core computer is healthy.

In the How to mentioned on TechNet, there is also a powershell script provided to help assist in the move of Windows Agents using the Powershell script:

$newMS = Get-ManagementServer | where {$_.Name –eq ‘<SecondaryMgmtServer.DomainName.COM>’}
$agent = Get-Agent | where {$_.PrincipalName –eq ‘<AgentComputer.Domain.COM>’}
Set-ManagementServer -AgentManagedComputer: $agent -PrimaryManagementServer: $newMS