Convert SBS 2003 domain to Server 2008 R2 Standard - will this work?

Question

I have been tasked with converting an SBS 2003 domain to Windows Server 2008 R2 Standard. The customer plans to expand past the limitations of SBS, and does not use Exchange Server at all. Here's the current set up:

City A: This is the client's original first location. There is one server here running SBS 2003. It performs domain controller and fileserver roles, and has all the FSMO roles because it's SBS.

City B: The client set up a branch at this location with a server running Windows Server 2008. It also acts as a domain controller and fileserver.

The client wants to move away from Small Business Server, so they have decided to upgrade the server in City A to Server 2008 R2 Standard. It will continue to provide the same services it is currently providing. They have opted not to purchase new server hardware, so the upgrade must be "in-place".

I am seeking feedback on the following upgrade plan:

1. Back up files and system state from SBS server using ntbackup
2. Shut down the SBS server and image the RAID5 array using Ghost or Acronis
3. Re-start the SBS server
4. Shut down the 2008 server in City B
5. Set up a desktop temporarily with Server 2008 R2 in City A and run DCPROMO
6. Shut down SBS server
7. Use temporary server to seize FSMO roles
8. Reformat and install Server 2008 R2 on original SBS box
9. Run DCPROMO on new 2008 R2 box and transfer FSMO roles to it
10. Install services and transfer files to new 2008 R2 server
11. Verify that domain is working for clients, then bring City B's server back online

And my back-out procedure:

1. Turn off servers in City A
2. Restore SBS server in City A using Ghosted image
3. Verify connectivity then restart server in City B

Answer 1

(Answering myself...)

No, this won't work. Shutting down the server in City B while the FSMO roles are seized from the server in City A will effectively orphan the server the City B, as it will no longer have a point of contact into the network.

Alternate solutions would be to leave the server in City B online, or even to use that server to seize FSMO roles.

Answer 2

I think you ought to seriously consider a swing migration for this. I've used it successfully going from plain Windows 2003 Server to SBS. Though I've not personally done it, I imagine you can also use it to go from SBS 2003 to Server 2008. It is super easy to follow.

http://www.sbsmigration.com/