Incorrect sources.list after upgrade of 16.04 to 18.04

[evansj2]

I have two servers at home which were running Ubuntu 16.04. I upgraded both of them to 18.04 a few months ago using sudo do-release-upgrade as described in the official docs. The servers themselves are very different, one is a fairly feeble mini-ITX machine and the other is a 16 core AMD64.

The mini-ITX upgraded fine, the other one had all sorts of problems which I eventually resolved, and I'm kicking myself now that I didn't make any notes about what the problem was. It runs OK now, mainly services inside a handful of docker containers. However I'm now in the following situation:



Both servers are running kernel 4.15.0-36-generic
Both servers think that they are running 18.04 LTS:



$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 18.04.1 LTS
Release: 18.04
Codename: bionic



One of the servers has xenial in its /etc/apt/sources.list and the other has bionic.


The server which is OK:


$ grep -v -E '^#|^$' /etc/apt/sources.list
deb http://gb.archive.ubuntu.com/ubuntu/ bionic main restricted
deb http://gb.archive.ubuntu.com/ubuntu/ bionic-updates main restricted
deb http://gb.archive.ubuntu.com/ubuntu/ bionic universe
deb http://gb.archive.ubuntu.com/ubuntu/ bionic-updates universe
deb http://gb.archive.ubuntu.com/ubuntu/ bionic multiverse
deb http://gb.archive.ubuntu.com/ubuntu/ bionic-updates multiverse
deb http://gb.archive.ubuntu.com/ubuntu/ bionic-backports main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu bionic-security main restricted
deb http://security.ubuntu.com/ubuntu bionic-security universe
deb http://security.ubuntu.com/ubuntu bionic-security multiverse

The server which still has xenial:


$ grep -v -E '^#|^$' /etc/apt/sources.list
deb http://gb.archive.ubuntu.com/ubuntu/ xenial main restricted
deb http://gb.archive.ubuntu.com/ubuntu/ xenial-updates main restricted
deb http://gb.archive.ubuntu.com/ubuntu/ xenial universe
deb http://gb.archive.ubuntu.com/ubuntu/ xenial-updates universe
deb http://gb.archive.ubuntu.com/ubuntu/ xenial multiverse
deb http://gb.archive.ubuntu.com/ubuntu/ xenial-updates multiverse
deb http://gb.archive.ubuntu.com/ubuntu/ xenial-backports main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu xenial-security main restricted
deb http://security.ubuntu.com/ubuntu xenial-security universe
deb http://security.ubuntu.com/ubuntu xenial-security multiverse
deb https://apt.dockerproject.org/repo/ ubuntu-xenial main
deb http://archive.ubuntu.com/ubuntu/ xenial-proposed restricted main multiverse universe
deb [arch=amd64] https://download.docker.com/linux/ubuntu bionic stable


The "broken" server thinks that it's up to date:


$ sudo do-release-upgrade
Checking for a new Ubuntu release
No new release found.

I only noticed when I thought it was weird that sudo apt update on that server hasn't found anything to update in the last few weeks and normally there's at least one updated package every day or so.

Can I fix this by just updating /etc/apt/sources.list or is there more to it than that?

[evansj2]

OK, I manually updated /etc/apt/sources.list and changed all of the xenial references to bionic. apt subsequently installed ~200 updates and after a reboot everything seems to be working OK.