Getting Samba running on CentOS 7.9

["Robert G. (Doc) Savage" <dsavage@peaknet.net>]

Background:  About six years ago a friend was having fits with Windows Small Business Server running on a 2010-vintage Dell T110 server. Something was continuously filling up the logs. When I learned that the only thing they were really using the server for was as a network file server for about 30 years of business records and AutoCAD projects, I suggested converting from Windows SBS to CentOS 7 and Samba 3.  Their client machines include one Windows 7 (now 10) PC, 3-4 Macs, an E-size HP plotter, and a Sharp color laser printer.

The conversion went fairly easily. For some strange reason the Macs had problems connecting with NFS, but none at all using SMB/Samba. Electrical power glitches caused loss of network connectivity from time to time, but we never lost any of the records or projects. I'd get panicky calls every once in a while, but those problems were typically fixed by service restarts, and occasionally by a PC reboot.

About three months go, however, something hit the server hard. Samba and NFS services refused to start. Indeed, the MATE desktop refused to start. Something about nfs3-bind permissions. After struggling with it for about a month, I gave up. I backed up everything and reinstalled CentOS 7.9 from scratch. Getting the NFS service back online was easy. Samba was a totally different matter. No matter what I do, I can't seem to get the Macs to connect to the shared directories on the server. I know NFS works because my F33 laptop can connect to the shared /samba folder.

Are there any SILUG folks running Samba 4 on CentOS/RHEL 7 that I can compare notes with?  I suspect what's causing the problem is one of those obscure secondary configuration settings like firewall or ACLs. If yours works and mine doesn't, I'd sure like to do a side-by-side comparison.

--Doc