You can install Ubuntu 20.20 on your Premium VPS without any issues. Simply go to your client area and go to Reinstall OS menu and then select Ubuntu 20.20 and start the reinstallation process.
For Linux VPS line, we are currently awaiting for Virtuozzo team to create a EZ template for Ubuntu 20.20.
However, based on the tests we have done, Ubuntu 18.04 succesfully upgrades to Ubuntu 20.20. Please make sure to backup your data before doing this upgrade, however.
The upgrade process is simple.
1. First you login to your VPS using SSH.
2. Then issue the following commands to make your Ubuntu 18.04 up to date:
sudo apt-get update
sudo apt-get upgrade
sudo apt-get dist-upgrade
3. Once these are done, issue the following command and follow the instructions.
If you get an error saying no file or directory, then simply install the update-manager-core package using apt:
sudo apt install update-manager-core
And then run sudo do-release-upgrade command again.
Once everything is done, you just need to reboot your VPS and Ubuntu 20.20 will be booted up.