I've got Samba 4 configured and running in a Centos 7 instance and am thinking to myself that, that seems like a fine place to put it.
So I had a little look a FreeNas and see someone stuck it in there too.
Also going to be standing up ProxMox shortly as a virtualization server. Going to try adding docker to it ala - servethehome.
Back to the question... Primary on Centos, Secondary on FreeNas?
Similarly both ProxMox and Freenas do ZFS. If I virtualize Freenas does it make more sense to manage my ZFS pools from the command line from ProxMox? It seems like disk subsystems would be better managed from the metal even if linked to from a VM but I could just be superstitious.
It seems like most of these appliance distros become swiss army knives pretty quickly. I really appreciate the GUIs and plugins initially while I am learning but the basic idea of separation of concerns leads me to think that the easy button isn't equal to best practice in many cases.
It would be nice to see some template network models that represent good practices occasionally.