upgrading to 20.04

[Ralf Mardorf]

On Sun, 26 Apr 2020 11:19:42 +0200, Bo Berglund wrote:
>If I have installed the mate-desktop will an Ubuntu upgrade from 18.04
>LTS also bring along the mate-desktop or is it not touched by the
>upgrade?

All packages from official repositories are upgraded. Some packages
might have changed their names or became useless. If a package changed
it's name, a meta-package for transition will solve this issue.
Packages that are unneeded will be removed.

However, some packages might be wanted by the user, but discontinued
by the packagers.

An example is ROXTerm:

https://packages.ubuntu.com/search?suite=xenial&searchon=names&keywords=roxterm

It's available for the release I'm using, 16.04 LTS, but if you click
any other release, you'll see it doesn't exist anymore.

A while ago upstream discontinued ROXTerm, that's why it was
dropped by the packagers, too, but also a while ago ROXTerm
development continued again.

>After all I have set the login to be to mate desktop and I have
>configured it to run as a headless server without suspending due to
>the lid being closed etc. I connect via SSH and VNC.
>
>Or am I better off taring up my home dir to an external drive and then
>wipe and install from scratch?

No! As Colin, I'm in favour of upgrades, too. OTOH it could depend on
the Ubuntu flavour, at least one is known, to better do a new install,
but for good reasons I will not mention the name of the flavour. Ask on
the mailing list of the flavour you are using and eventually on the
mailing list of a falvour meta-package you are using. I suspect the
Mate flavour is not affected.

>Are system installed files in ~/ compatible between 18.04 and 20.04?

Yesno. Since you already made a backup of etc/, an upgraded software
might introduce new features and those features might require a new
config.

When doing the upgrade you get asked if the upgrade should keep your
config or replace it or do something else.

If you keep your edited config, the new config gets an extension, so
it's not used by the software, but you could manually compare and edit
the config.

You might have edited

/etc/foo-bar.conf

if so, an upgrade would install a plain config as

/etc/foo-bar.conf.dpkg-new
                  ^^^^^^^^ or similar.

Since I'm also using the rolling release model distro Arch Linux, I use
"meld" to compare and if necessary to edit configs.

On Ubuntu I would do the same, just not on a more ore less daily basis.

Install https://packages.ubuntu.com/bionic/meld and after an upgrade run

sudo meld /etc/foo-bar.conf /etc/foo-bar.conf.dpkg-new

Note, if you should backup the complete root directory, don't do this
while your install is running. Some file systems allow to backup a
running system, by the UNIX dump command, which will backup a snapshot,
but GNU is a recursive acronym for "GNU's Not Unix", so always backup
from either another install or a live media.