We currently have a single Exchange 2007 Server on Windows Server 2008. It's also a DC and I'd like to split the DC role to a different box.
Is this doable without migrating the mailboxes off to a temporary box, re-installing and migrating back? I.e. can I just demote the server without breaking Exchange completely? I know this was quite painful with Server 2003/Exchange 2003, so I'm trying to get an idea of how much different the process is for Server 2008/Exchange 2007.
Unfortunately the process for Exchange 2007 is pretty similar, in that MS do not support changing the role of an Exchange server, once Exchange is installed. This article states:
If you are running Exchange Server 2003 or Exchange Server 2007 on a domain controller, using the domain controller promotion tool (DCPromo) to change the computer role is not supported, and it is known to break components such as Microsoft Outlook® Mobile Access.
Whilst it doesn't state that it definitely won't work, I wouldn't want to risk my Exchange infrastructure by trying, as if it goes wrong it's going to cause you some pretty major headaches. Yes doing a swing migration to a temp box is a bit of a pain, but at least you know it will work.