I want to be able to keep the current SBS 2011 server as an Exchange Server 2011 only. The current server houses all of Active Directory. I want to be able to keep the server "alive" and also keep DNS role installed. I am migrating to Server 2012r2, the old server needs to only house 2 roles Exchange 2010 and DNS if possible, as well DNS on the new server. What is my best approach to maintain Exchange in-tact so to speak. I can transfer the FSMO roles, but then would I demote the old server and then promote. Please help, I am doing this migration in a week and have all all issues pre-migration done.