- sudo do-release-upgrade
Checking for a new Ubuntu release
No new release found
-doption in order to use the development release:
- sudo do-release-upgrade -d
You will now see the packages that are going to be upgraded and the changes that are going to be made. Note that the upgrading process can take several hours, and you can’t cancel the process once Ubuntu is upgrading.
After the upgrade has finished, you can confirm your server is running on the new version by executing the command
Source: How To Upgrade Raspberry Pi Ubuntu Mate