[Samba] Samba4: fileserver on a box other than a DC

[steve]

Hi
Our fileserver is currently on DC1 in a 2DC domain. We are running out 
of space on that box.

Is there any possibility of being able to run smbd on another box (not 
necessarily a domain controller) by syncing the data over to it from 
DC1? We also run NFS on some of the same data. I can already see this 
turning into a naming, IP and Kerberos nightmare.

What would be the provision server-role= parameter for a machine that 
was going to be a fileserver but not a DC? Is that even possible? If it 
is going to be a domain member, maybe I should not provision?

What command would I use to join the machine to the domain so it becomes 
just an ordinary member?

Cheers,
Steve