As pointed out by one of our esteemed colleagues a few days ago, FermiLab recently announced that they are phasing out Scientific Linux, in favor of CentOS v7. Since my cluster is built around Scientific Linux, I wanted to see how CentOS would play / interact with the system.... so today I installed the newer OS on one node. Frankly, I don't see any real difference between the two. Both are based on Red-Hat, they run Gnome GUI, and offer more-or-less the same install packages. They even interchange repositories. The only real difference I see is that CentOS is a bit slimmer..... AND allows for an easier installation of Python3/Idle3 over the top of Python2.7/Idle without having to uninstall anything. After installing the OS, and setting up the network addresses, the node worked just like my Sci-Linux nodes. SO... my conclusion about the CentOS vs Scientific Linux transition is: "meh...whatever.... no big deal.... who cares?".