[Samba] Problem with Samba 3 with Samba 4 AD-DC

[Joní Kremer]

 Good morning people, everything fine? I wanted to see if anyone could help
me with the following problem: I have a samba version 3 file server running
and working.. Now I have set up a UBUNTU 18.04 server with SAMBA 4 AS
AD-DC.
It is an activy directory - Domain Controller of my network..

Question: How do I integrate Samba Server 3 with my file shares into my
Samba 4 - active directory - Domain Controller.. Should I include some
lines in smb.conf?
How do I do that? I look forward to any help..
Thank you    Joní