We are going to upgrade our domain controllers, and am very confuse between 2 scenarios Upgrade in place or fresh installation then migrate?, I have been doing some research into the subject but nothing that quite matches our situation. In my environment we have 5 phasical DC's and 3 virtual Dc's all running win server 2008 r2 domain controllers. A primary DC is located at our main site and a secondary DC located at our disaster site (connected by WAN). What is the proper upgrade path for migrating both servers to 2012 r2 and upgrading the forest/domain functionality level to 2012? and do i will lose any kind of data like OU's DNS record or any such thing like that?
Kindly need your support to be on the right track.
Thanks.