I am working on upgrading my domain from two domain controller running server 2003 to 2008 R2. Everything is in a VMWare environment so there are no real hardware considerations. My current domain controllers are 32bit SP2 and run both DNS and DHCP services. I was wondering if it might make sense to attempt an in place upgrade of the servers rather than doing a clean install and trying to migrate DNS and DHCP services over to a new server. We have all static addressing on our LAN and changing the DNS on every device would be a huge task so I'm looking for ways to avoid that.
Is it possible to do an in place upgrade from the 32bit version of Server 2003 to 2008 R2 which is 64bit? If so what is your opinion about potential problems I might encounter? If the in place upgrade is unwise or not possible what would you recommend to deal with the DNS issue? In a nutshell my thought was to integrate the new servers, promote them to DCs, move the roles over, demote the old servers, then have the new servers assume the IP addresses of the old servers. I'm worried that this might cause some problems but I can't think of any specific issues myself. I would greatly appreciate any assistance you could offer, thanks!