The first part of the upgrade went well, but after rebooting, the system freezes. The screen remains black, the cursor stops blinking after a few seconds. The only possible action is Ctl-Alt-Del.
With the recovery mode, it’s possible to enable networking and drop to root shell prompt. What should I do from there?
I made some progress: with systemctl set-default multi-user.target the machine reaches the text login. But the system freezes in graphic mode: systemctl set-default graphical.target
I’d check whether a kernel module failed to build for the 7.x kernel, since the text login works and only the graphical target freezes. From the text login run:
dkms status
Any module that doesn’t show installed for the kernel from uname -r didn’t build. If evdi is in that list, remove it the same way ogra described above.
If nothing is missing there, set graphical.target again and reboot until it freezes. Then press Ctrl-Alt-Del, pick recovery mode in GRUB, drop to the root shell, and read the errors from the frozen boot:
journalctl -b -1 -p err
Errors from gdm, nvidia, or amdgpu in that output identify the driver to reinstall or remove.