We're currently running Exchange 2003 SP2 in a Server 2003 Native Mode AD forest with a single domain and two sites. We want to get to Server 2008 R2 AD DCs and Exchange 2010 SP1.
We're also starting to leverage virtualization (VMWare ESX/ESXi 4.0/4.1) and a new SAN.
I'm wondering if I should focus on upgrading the domain controllers first, or exchange first and the DCs later. I won't be able to have all 2008 DCs until I add new hardware at my second site, so I'd have a mixed mode 2003/2008 domain for some time, and we will have one DC be a physical box versus relying entirely on virtual systems.
Are there any issues adding a 2008 DC to a 2003 native mode domain that would impact Exchange 2003 in some unexpected way?
Just looking for hidden gotchas, plus the best strategy in terms of what to tackle and in what order.
I saw a very useful "Rapid Transition Guide" for Exchange 2010 that I downloaded from a thread on Experts Exchange: http://www.experts-exchange.com/Software/Server_Software/Email_Servers/Exchange/Q_26626732.html
And I own a copy of the MS Exchange Server 2010 Inside and Out, which is helpful.
Best Answer
As long as the forest functional level is at least 2003, I would start with the upgrade of exchange from 2003 to 2010. The upgrade of the domain from 2003 to 2008 is relatively simple compared to exchange and any issues you run into won't be compounded by the 2008 DC upgrade complexity. Once the exchange upgrade is complete it will certainly not impact exchange to upgrade.