Executive Summary: Fedora 27 to 28 upgrade leaves desktop locked up.

Linux Fedora 28 was released yesterday and I missed the note!

So first thing this morning I sit down at my testbed machine: a dell optiplex 755 (circa 2008) – intel core2 quad Q6600 @2.4GHz, 4GBDDR2, Seagate 250GB sata drive.

I was running Linux Fedora 27 desktop and it had an icon for software updates. All of those were installed and then rebooted. The only remaining item was the fedora 28 upgrade. It was downloaded and then the install started. It did not take long.. less than 1 hour and it rebooted again.

And that is where the problem is. It appeared to be locked up and unresponsive to mouse or keyboard.
A manual power cycle and some fiddling with the grub2 options (removing rhgb and quiet), gave the old command line startup display.
It got to

started gnome display manager
started virtualization demon
started user manager for UID42

then locked up, no key responds no mouse. cannot ssh connect. totally dead to keyboard.
try replugging keyboard, mouse, no change.

Wow. Not even a kernel crash!
Tried manually cycling power several times, same results.
Next tried using the lat fedora27 kernel… SAME results!
Tried the grub rescue option.. SAME results… Arrgg!

After an hour of research on the internets, I found something that works… adding the parameter nomodeset into the /boot/grub2/grub.cfg kernel line (the one with the rhgb and quiet parms).
recompile with the command grub2-mkconfig and reboot!

nomodeset turns off video mode drivers from within the kernel until the graphical desktop has loaded.