This evening I had to reboot a server that was the server that currently all of the files are served from because updates required it. It did not boot. It took me three hours to get it to boot. Something in new nvidia drivers conflicted with kernel-nfs-server used to serve those files and the system purged the latter including the /exports file that tells it what machines to make the files available to.
I have solved the video conflict by removing the nvidia drivers and using the Linux nouveau drivers instead. They are slower but it’s not like I am going to play video games on this machine. They are adequate for everything else.
I am now rebuilding the exports file by hand. Hope to have everything operational again in a couple of hours. I will focus on the most used services first.