Ubuntu latest LTS is now released, why can't I upgrade from previous LTS? And how can I force the upgrade? [duplicate]
The answer is in the Release Notes
14.04 LTS to LTS upgrades will be enabled with the 16.04.1 LTS point release, in approximately 3 months time.
Stability in an LTS release comes first.
NOTE: With Ubuntu 18.04 LTS it is the same with the first point release that is due out late July 2018. The steps below should be the same, but just warning that my experience with the upgrade from 16.04 to 18.04 this time did not go as smoothly. I recommend waiting for the first point release (18.04.1) in July before upgrading.
Like it says in the Release Notes that the LTS upgrades will be enabled with the 16.04.1 LTS point release, in approximately 3 months time.
However, if you don't want to wait, the following command will tell your Ubuntu installation to install the latest devel-release:
WARNING: Make sure that your system is up to date, all applications are running well, and that there are no partition errors. Recommend running fsck on your system from Recovery Mode before upgrading.
For console/text only
sudo do-release-upgrade -d
For GUI interfaces from a terminal window or by using Alt+F2
update-manager -d
which will run the update-manager and show that a newer version 16.04 is available for upgrade. Follow the instructions on the screen to upgrade to Ubuntu 16.04LTS.
NOTES from the upgrade that I have observed:
The upgrade process will disable all of the 3rd party repositories that are in the /etc/apt/sources.list.d/ folder. It also backs up your old /etc/apt/sources.list to /etc/apt/sources.list.distUpgrade. The files will not be deleted but the repository lines contained within the files will be commented out, except for in the sources.list.distUpgrade file. I found that I was not able to remove the comment in front of the repository and have it just work with the apt-get update command. Instead I had to re-add the repositories by either adding them manually to the /etc/apt/sources.list file or by adding them with the add-apt-repository command again.
PlayOnLinux repository is not Xenial compatible yet. If PlayOnLinux is installed, it will update from the Xenial repositories.
EDIT: Google and VirtualBox repos have been updated.
Adding Google Chrome and VirtualBox repositories back will show the following messages during an apt-get update. These have been reported here and hopefully they get updated soon. The applications will still update without any problems.
W: http://download.virtualbox.org/virtualbox/debian/dists/xenial/InRelease: Signature by key 7B0FAB3A13B907435925D9C954422A4B98AB5139 uses weak digest algorithm (SHA1)
W: http://dl.google.com/linux/chrome/deb/dists/stable/Release.gpg: Signature by key 4CCA1EAF950CEE4AB83976DCA040830F7FAC5991 uses weak digest algorithm (SHA1)
The graphics-drivers repository for Ubuntu that contains the NVIDIA drivers will have to be added back. Simply running sudo add-apt-repository ppa:graphics-drivers/ppa works with Xenial and updated drivers after install. I did need to copy my old xorg.conf file back for my monitors to work properly.
fail2ban had to be purged with my old custom config files. Reinstalled without issue and appears to be working fine.
Other miscellaneous applications needed to be reinstalled. sudo apt-get install --reinstall <application>
Overall, the upgrade went well and feels really stable.
$ cat /etc/*release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=16.04
DISTRIB_CODENAME=xenial
DISTRIB_DESCRIPTION="Ubuntu 16.04 LTS"
NAME="Ubuntu"
VERSION="16.04 LTS (Xenial Xerus)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 16.04 LTS"
VERSION_ID="16.04"
HOME_URL="http://www.ubuntu.com/"
SUPPORT_URL="http://help.ubuntu.com/"
BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"
UBUNTU_CODENAME=xenial
$ uname -a
Linux terrance-Linux 4.4.0-21-generic #37-Ubuntu SMP Mon Apr 18 18:33:37 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 16.04 LTS
Release: 16.04
Codename: xenial