Demoting a DC which also runs Exchange 2010

Initially when setting up Exchange 2010 CAS I ran into problems with permissions. I got around them by promoting the server to be a DC with a GC.

The Server was initially installed with 2008 R2 Standard ED. I need to do an in-place upgrade to ENTERPRISE which requires me to demote the DC on this server first (AKAIK).

This is a production server.

My question is: How best to achieve this?

If you can only offer some advice for possible problems I would greatly appreciate that too.

Solution 1:

First thing is first, figure out what the problem was with the CAS installation and figure out how to do it correctly.

After you have that sorted out, you shouldn't run any Exchange roles (or any other roles except DNS for that matter) on a Domain Controller. If you're buying an Enterprise license, you're entitled to run 4 VMs on the same piece of hardware with a single Enterprise license. You should do this. This is how I would handle it.

1. Resolve your outstanding permissions issue.

2. Install Hyper-V Server (or other virtualization product).

3. Install at least two 2008 R2 VMs.

4. Promote one of them to a DC and make it a GC.

5. Make the other server a CAS for Exchange and do all of the stuff associated with transferring the CAS role to another server.

6. Take the old CAS offline and uninstall Exchange from that box.

7. Run dcpromo on the old box and demote it.

This requires extra hardware, but it's your best bet. Seriously, fix your original problems then separate the roles.