Upgrade Ubuntu 18.04 to 20.04 LTS

Ubuntu 20.04 LTS (Focal Fossa) was officially released on April 23 after two years since the release date of version 18.04.

Ubuntu 20.04 features the latest LTS kernel 5.4 and it supports ExFAT file system by default so I can explore files in my Windows system wihtout any barries. It bring many other new features and higher performance as well compared to 18.04.

Commands to upgrade from Ubuntu 18.04

$ sudo apt update && sudo atp upgrade -y
$ sudo systemctl reboot    # Login Loop issue may occur after reboot

$ sudo apt dist-upgrade
$ sudo apt autoremove
$ sudo apt install update-manager-core -y
$ sudo do-release-upgrade

$ cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=20.04
DISTRIB_CODENAME=focal
DISTRIB_DESCRIPTION="Ubuntu 20.04 LTS"

Issues during upgrading process

1. Login Loop Issue: I cannot login system with a valid password after the first reboot:

   • I googled and refered some online solutions like chown username: username .Xauthority, change grub file, etc., these ways cannot fix my issue:
     • I cannot find an .Xauthority file in my home directory (the reason may be my computer is a dual-system)
     • Other issues will occur after trying them
   • The solution is: Press ALT + F3 to switch to another terminal, and excute the upgrade commands once again(without running the reboot command) and continue the upgrading process. The upgrade can be done in this terminal, and the issue will be fixed automatically once Ubuntu 20.04 is installed.

2. It Upgraded to Ubuntu 19.10 at first, not 20.04 directly. I don't actually know the reason, solution:

   • Repeat the upgrade commands to upgrade from 19.10 to the latest 20.04

3. errors were encountered while processing package mysql-server-8.0 caused upgrade abortion, solution:

   • Remove mysql-server by apt --purge remove mysql-server instead of apt remove mysql-server
   • This will avoid the upgrade abortion other than trying to find a way to install mysql-server correctly, and we can install it after the upgrade.

4. No slider to adjust screen brightness due to change of grub file, solution:

   $ sudo  vim /etc/default/grub
   GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" # modify to: quiet splash
   $ sudo update-grub
   $ sudo reboot

5. Logo Splash shows twice when booting or rebooting:

   The first time is when shuting down/booting before entering the grub boot menu, the second time is when kernel loads Ubuntu. I did't experience this on Ubuntu 18.04, and the whole boot/reboot process takes more time in Ubuntu 20.04. Somebody said it's a default behavior for the newly installed systems. However, I don't like this.

• By editing the grub file(see above), changing kernel parameters quiet splash to quiete, this will hide the splash during kernel loading Ubuntu. However, if there are some BIOS errors at this phase, they will display on screen.

Follow-up Settings/Reading Material

• Things to do after installing Ubuntu 20.04 Focal Fossa Linux
• 10 Tips to Speed up Ubuntu