17.10 to 18.04 upgrade freezes during boot
Try logging in to your default desktop environment from the tty virtual console. The virtual console can be accessed by pressing the keyboard combination Ctrl+Alt+F3 after the computer gets stuck when booting it. Login to the virtual console with your username and password and run the following command.
sudo systemctl start graphical.target
If that doesn't work, switch the login display manager from gdm3 to lightdm. LightDM is a more lightweight login display manager than gdm3.
sudo apt install lightdm
sudo dpkg-reconfigure lightdm
sudo reboot
sudo dpkg-reconfigure lightdm
will open up a new window allowing you to select lightdm as the default login display manager. Use the arrow keys to select lightdm, press the Tab key to put the focus on <OK> and press Enter. Then reboot by running sudo reboot
Try booting from Xorg instead of Wayland. Edit /etc/gdm3/custom.conf
with sudo nano /etc/gdm3/custom.conf
, uncomment #WaylandEnable=false
so it is WaylandEnable=false
and run sudo dpkg-reconfigure gdm3 # select gdm3
If that doesn't work either see if you can at least switch to text mode (for troubleshooting purposes) with no GUI stuff like the X server running.
sudo systemctl start multi-user.target
Turns out that the problem isn't a gdm3 vs lightdm problem. It's a gdm3/wayland problem with older Intel GPU's. To fix...
In terminal
...
cd /etc/gdm3
# change directorysudo pico custom.conf
# edit this file
Find and change:
#WaylandEnable=false
To this:
WaylandEnable=false
Save the file.
sudo dpkg-reconfigure gdm3
# select gdm3 DM
Select gdm3 and OK.
reboot
# reboot the computer