hi colleagues, 

I am planning to move SEPM 12.1.3xx which hosted at windows ssrver 2003 R2 to Windows server 2012. Please help how to do this. 

Thanks you in advance.

Rico 

Hostname and IP staying the same?

Follow the direction in this article:

How to move Symantec Endpoint Protection Manager from one server to another server

https://www-secure.symantec.com/connect/articles/how-move-sepm-one-server-another-server

How to move Symantec Endpoint Protection Manager from one server to another server

How to move SEPM from one server to another server.

https://www-secure.symantec.com/connect/articles/how-move-sepm-one-server-another-server

What is the IP and Hostname, is it same or different?

How many client in your network..

If incase SEPM IP/Hostname detail is different then you can please follow the replication method.

Below article is for your help.

How to move Symantec Endpoint Protection Manager from one server to another server

How to move Symantec Endpoint Protection Manager from one machine to another

A) Replication method

1. Install Symantec Endpoint Protection Manager on MACHINE_2
   NOTE: The version installed to the new server must be the same version as on the old server. The new management console can be migrated to a newer version once the transition is complete.
2. In the Management Server Configuration Wizard panel, check Install an additional site, and then click Next
3. In the Server Information panel, accept or change the default values for the following boxes, and then click Next
   • Server Name
   • Server Port
   • Server Data Folder
4. In the Site Information panel, accept or change the name in the Site Name box, and then clickNext
5. In the Replication Information panel, type values in the following boxes:
   • Replication Server Name
     The Name or IP address of MACHINE_1
   • Replication Server Port
     The default is 8443.
   • Administrator Name
     The Username used to log on to the old console.
   • Password
     The password used to log on to the old console.
6. Click Next
7. In the Certificate Warning dialog box, click Yes
8. In the Database Server Choice panel, do one of the following, and then click Next:
   Check Embedded database or Microsoft SQL server (whichever database type you'd prefer to install), then complete the installation.
9. Log in to the new SEPM on MACHINE_2 and ensure that all the clients and policies have Migrated successfully.
10. Click Policies > Policy Components > Management Server Lists > Add Management Server List
11. Click Add> Priority and a new Priority would get added named as "Priority2"
12. Add MACHINE_1 under Priority 2 and add MACHINE_2 under Priority 1, and assign thisNew Management Server List to all the groups.
13. Wait at least one replication cycle.
14. Stop the "Symantec Endpoint Protection Manager" and "Symantec Embedded Database" service on MACHINE_1 to verify whether all clients now report to the new SEPM on MACHINE_2
15. Once verified that all the clients are reporting into the new SEPM, and have moved away from the old one, proceed to the next step.
16. Delete the Replication Partner from MACHINE_2 SEPM: Click on the Admin button | Under View Servers, Expand Replication Partners and select the partner to delete | Under Tasks, choose Delete Replication Partner | Type Yes when asked to verify deletion of the replication partner.
17. After the successful Migration, uninstall SEPM from MACHINE_1

I noticed that after replication, and giving it a few days in general to catch up. My DB (embedded) on the original 2003 server is huge but on the 2012 server, it is a fraction of the size. Is this correct? I don't want to disable replication between the new and old server if the information isn't proper.