I have two boxes that I'm in the process of upgrading from 2008 R2 to 2012. One of my main concerns is with regards to the DFS volumes replicated between the two boxes. In that past I've had crazy stuff happen such as DFS deciding to delete everything in volumes, so I don't particularly like to prod DFS any more than necessary. It appears to be a glass house at times.
My question is primarily with regards to if upgrading should be safe or would it be better to backup and destroy the DFS volumes before upgrading? Backing up won't be easy as there isn't enough space anywhere else on the network (other than these two boxes) to store the volumes' ~5 TB of data.