I'm working on building a NAS for a media server and I'm trying to figure out what OS to choose. I'm not apposed to paying for something if it's worth it, but free and open source is always appreciated. Drive pooling is a must and support for raid would definitely be a pro. On top of that I'd like to run all the arr's, Plex, Tautulli, and a few other things. Any suggestions would be much appreciated!