Ubuntu 16 was released a few weeks ago, the latest version and a LTS release, which means long term support (5 years). All even numbered releases are LTS. I’ve been running Ubuntu since version 10 and updated three machines to Ubuntu 16. A year or two ago I switched to the XUbuntu variant because I don’t like the Unity interface and XFCE is faster and lighter on CPU and RAM. My advice is to stick with Ubuntu 14, if that’s what you’re already running. At least for now.
First, if you have a laptop that needs support for power management, you need the version 4 Linux kernel and must already be running Ubuntu 15. Just keep running it. If you have a desktop, you’re probably running Ubuntu 14, which is a solid release and still supported.
Second, Ubuntu 16 has few practical improvements or upgrades that you might notice. The only difference I’ve noticed is that the Openconnect VPN script is fixed; Ubuntu 15 required a route command after connecting; Ubuntu 16 is fixed and does not. Ubuntu 14 never had this bug.
Third, the Ubuntu 16 upgrader is broken and crashes, so if you try to update you’ll have to fix and complete it manually.
Fourth, Ubuntu 16 has a serious bug: a memory leak in the Xorg process. Previously it used 50 – 100 MB of RAM. On Ubuntu 16 it slowly but constantly grows, after a couple of days reaching a couple of GB, until the system starts swapping. You need to log out to kill the Xorg process and start a new one. This bug occurs only on my desktop using open source video drivers. The other desktop with Nvidia binary drivers, and laptop with Intel HD graphics do not have this bug.
Details: I updated two desktops and a laptop, all 64-bit. One desktop has a generic video card using open source drivers. The other has an Nvidia Quadro K600 using the Nvidia binary driver from the Ubuntu repo. The Laptop is a 2015 Thinkpad Carbon X1 with Intel HD graphics. All three were running Ubuntu 15.10, fully up-to-date, before upgrading, which was running great on all of them.
In all cases, I ran do-release-upgrade from a command prompt. It crashed – didn’t fail, but actually crashed – about halfway through, leaving my machine reporting itself as Ubuntu 16, but with apt-get in a broken state. To complete the install, I ran the following sequence of commands:
apt-get -f install
apt-get update
apt-get dist-upgrade
apt-get autoremove
I repeated this sequence until apt-get stopped reporting errors. This completed the install – at least I think so. All the repos seem to have updated, the system is running kernel 4.4.0, system reports itself as Ubuntu 16 and is running fine.
It’s nice to have VPN work without needing an extra route command. But unless you have a burning need to get on Ubuntu 16, I advise waiting for Canonical to fix the upgrader before installing.