Still having issues with mounting USB devices APFS vs GUID
I am still having a hard time with understanding the mounting issues when using mixed formatting schemes. Have a 2012 upgraded with a Samsung 860 1TB SSD running Catalina. It is not mounting GUID formatted USB drives or printers. Disk Utilities shows the top drive (the 860) as aGUID Partition Map. The subset shows a drive and is labeled Container Disk 1 with a subset listed as APFS container. The subset of that is listed as a APFS Volume and the data disk as an APFS volume.
Is there someplace I can go to help me understand how these different formats work and what to do to get them to recognize when a GUID needs to be mounted on an APFS and vice versa?
I have also noted that when I install High Sierra and above, on an internal drive, from and external USB drive (formatted GUID) that after the new system is installed and booted from, I can no longer see the drive That I just did the installation from!