Now that Ubuntu 20.04 LTS (Long Term Support) is out, here’s a quick guide to upgrade to Ubuntu 20.04 LTS. You can ONLY upgrade from either Ubuntu 18.04 LTS or 19.10. If you have older versions of Ubuntu, it may not work. I suggest you back up your VM before running the upgrade, so you can quicky recover if something goes awry. This upgrade process will require sudo access.
# login as root sudo -i # check your current version lsb_release -a # update packages apt update -y apt upgrade -y # reboot server reboot # remove old kernels apt --purge autoremove # install update manager core apt install update-manager-core # finally, perform the upgrade do-release-upgrade -d # reboot the server reboot # after reboot confirm lsb_release -a