Updating from Ubuntu 16 to 18
I had some problems when updating from U16 to U18 (Bionic Beaver). Here I share those problems and the solutions. In tty1
terminal I called the following commands:
$ sudo apt-get update
Initially the update failed because my computer could not locate a release file for one of the repositories. This was
the repository I added manually to the
$ sudo apt-get upgrade
$ sudo apt-get dist-upgrade
$ sudo do-release-upgrade
/etc/apt/sources.list file many months ago when I installed R. To
solve that problem I commented out that repository in the sources.list file. I was then able to proceed, updating and
upgrading, downloading the U18 files and installing them.
I have a dual boot Linux and Windows setup and have edited the file /etc/default/grub by commenting out
GRUB_HIDDEN_TIMEOUT=0. This meant that during the U18 installation I was asked whether I wanted to merge
these edits with the new grub file. I chose "no" and accepted the new grub file.
I then removed packages and was asked to restart the computer. This is when the problems started. On reboot, I went
into Ubuntu (rather than Windows) but it did not go to the normal Ubuntu log-in screen. Instead the computer looped
through three or four different screens, two black screens, and one which had a list of text with "[OK]" written in the
far left column. The first time it did this I thought there was an error so I switched off the computer and turned
it on again. The same looping occurred on reboot and the last line of text on one of the screens read:
Started GNOME display manager... p link was shut down....
I partially resolved this by following the steps in this
link. It was tricky to follow the steps. I could
move to a tty terminal using Ctrl+Alt+F7 and Alt+F2 but the screen-switching continued. I had to be very quick at
logging in and running the commands while the screen was on the terminal. Ultimately I switched my display manager
from gdm3 to lightdm and restarted. This was met with some success. On restarting, the screens no longer switched and
looped. I could now see the U18 log-in screen.
I attempted to log-in, the screen went black and the log-in screen reappeared. I could not advance into the GUI.
I could use the ttys but not the GUI. The problem was that the nvidia driver on my computer was not compatible with
my graphics card. This solution is described in this
link. The code nvidia-current
showed that my current nvidia driver was version 340. Compatible drivers $ sudo apt-cache search nvidia-[0-9]+$
did not include 340. However 367 was included so I ran:
$ sudo add-apt-repository ppa:graphics-drivers/ppa
$ sudo apt update
$ sudo apt install nvidia-367
$ sudo reboot
True success! I was then able to log-in to the GUI as before and access Ubuntu 18.04.
Alastair Clarke
31 August, 2019