When Canonical's Ubuntu Linux 18.04 arrived, this outstanding Linux distribution had only one little problem: You couldn't directly jump from the last Long Term Support (LTS) version, Ubuntu 16.04, to the latest version. Now, with the release of the first point Ubuntu 18.04 update, Ubuntu 18.04.1, you can finally do it easily.
Of course, you could always update from one version of Ubuntu to the other. You just had to have your home directory on another partition or drive. Since most people don't bother with that, upgrading was a chore.
Before making the shift remember Ubuntu 18.04 doesn't look or feel like 16.04, 16.10, 17.04, or 17.10. That's because Ubuntu has moving back to GNOME for its default desktop from Unity. If you want to stick with Unity, you must jump through hoops to replace GNOME with Unity.
Unity desktop development is continuing. But, it's no longer an official part of Canonical's Ubuntu's efforts.
Ready to go? First, as ever, back up your existing Ubuntu desktop. To do this, I recommend Ubuntu's default Déjà Dup or CloneZilla. Once done, check the restore to make sure you have a good backup.
You're now ready to upgrade to With Ubuntu 18.04.1. You do this with the following steps:
The upgraded Linux is about one and a half gigabytes so be ready for a long wait.
You can also upgrade from the shell with the following commands:
$ sudo apt update
$ sudo apt upgrade
This makes sure your Ubuntu is up to date. Next, follow this up with:
$ sudo apt dist-upgrade
This handles changing software dependencies with new versions of packages.
I then follow this up with:
$ sudo apt-get autoremove
This removes dependencies from uninstalled applications. You can do the same thing from the GUI desktop with the utility application Bleachbit. After that, it's time to get things ready for the big upgrade with:
$ sudo apt install update-manager-core
$ sudo do-release-upgrade
This will start upgrading your system to 18.04. Along the way, Ubuntu will ask you several questions about how to handle the upgrade.
It will be worth it. Besides Ubuntu 18.04's advantages, the 18.04.1 release, which is what you'll be upgrading to, also comes with the 4.15 Linux kernel. In addition, it also incorporates many other performance and security improvements.
If you want you can stick with Ubuntu 16.04. Its next update, Ubuntu 16.04.5, will appear in early August. Canonical will continue to support Ubuntu 16.04 until April 2021.