Here is the quick down and dirty on how to upgrade Ubuntu via the command line. If you have a firewall or an older version installed, then there may be some additional steps involved. Listed below is simply the bare minimum process from 16.04 forward.
Connect to your Ubuntu host and run the following cli commands:
sudo apt update
sudo apt upgrade
- Restart your host machine
- Make sure Update Manager is installed
sudo apt install update-manager-core
- Begin the upgrade with
sudo do-release-upgrade, you will need to accept several prompts.
- Verify upgrade