Arrived here when searching for solution to the Samba CentOS 7.4 update.
Thank you, saved my day, yesterday.
Now downloading the Nethserver iso, will set up a machine to install and test.
I've been using CentOS for a few years, taking care of 3 different SME systems, where two of them are in CentOS 6, and only one already in 7. Very dependent on Samba (no AD), all have a mix of Windows and CentOS clients.
Cheers from the beautiful North of Portugal.