I just want to precautionarily check something - I hope someone can help. I'm in process of designing a plan for moving forward our current setup (which is entirely based on Windows 2003 DCs) to Windows 2008.
I'm clear on the fact that Exchange Server 2003 is not officially supported to run on the Windows 2008 platform. I don't want to do this, and in fact in the long term we will be switching to Exchange 2007 to achieve 100% Win 2008 based network.
HOWEVER - I would like in the interim to be able to migrate some of our DCs and member servers to Windows 2008, whilst keeping our existing Exchange Server running with Win / Exchange 2003, just for the moment. I'm aware that 2008 likes to make some schema changes - at least I assume it does, as all the docs I've read indicate that at least adprep (and possible forestprep) has to be run before adding Win 2008 DCs into our Active Directory. The question in my mind, is will these changes effect the running of Exchange 2003 running on this other Win 2003 server? Could it create schema mods that actually stop Exchange running properly elsewhere?
I appreciate there are different domain and forest modes in Win 2008 - to clarify, I will be running in the mode that still embraces Windows 2003 DCs, as well as 2008.
I guess the question is has anyone done this, and were there any putfulls? I assume it must be possible, as how else would one migrate an Exchange 2003 system to the newer 2007? I just don't want to jump head first in to this, if any of you have found this to be a pig and can help! I have been unable to find sound Microsoft documentation on this issue, but if anyone has found this info I'd be grateful.
Any input, as ever, very much appreciated.