Media Server (with MSDP) Upgrade OS from 2008 R2 to 2012 R2

IHAC, that wants to upgrade from 2008 R2 to 2012 R2 on their media servers.  Currently they are running NetBackup 7.6.0.2 and I figured we should update the NetBackup to 7.6.1.1(or 2) prior to any OS upgrade so the NetBackup will work.

I was also thinking we should be able to do the following if upgrading the OS is a bad idea:

1. On the GUI set the media server to be deactivated
2. Stop NetBackup on the media server
3. Backup Registry (just in case… don’t see why I would need it)
4. Unmounts the MSDP disks
5. Install Windows 2012 R2 with the same Server name and IP.
6. Install NetBackup on the new server
7. Stop NetBackup on the media server
8. Mount the MSDP disks
9. Start NetBackup on the media server
10. On the GUI set the media server to be active and see if I can see the disk pool.

Those steps above seem too easy on face value… I got be missing something logically.

Anyway has anybody done an OS upgrade on a Media server running NetBackup with an MSDP pool?  Did it work?  What steps did you do to protect the MSDP?