Collecting information...what do you do when upgrading to 2012 R2?

[h4x0r]

Collecting information and seeing what others out there do when it comes to upgrading their server OS. This mainly came about through a discussion with a co-worker as we were retiring some Server 2003 boxes...what do you do when a wipe and fresh install is not an option? It may seem like an elementary question, but to me that would be the ideal process (wipe+fresh install), but it would seem that there are circumstances that don't make that a viable option, such as servers hosting various applications. I would think that if the function of the server is nothing more than, say, a file server, that upgrading would not be an issue (assuming that wiping the server is still not an option)...but I wanted some more input from the community to see what methods others are using.

[DPB]

Convince your boss to go virtual and then create VMs that you can migrate to. VMs are a game changer.