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user14845796
Asked: 2020-12-18 11:13:40 +0800 CST

Will Uninstalled Components get (Re)Installed after Kubuntu 18.04 LTS to 20.04 LTS Update?

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I have researched this and come up with several different answers, but nothing solid.

I had installed Kubuntu 18.04 LTS on my laptop two years ago. Shortly afterwards, I had removed the Akonadi/Kontact suite of apps and several other components that are unnecessary for my use. It took me quite a while to go through all of the deps and figure out what I could and could not safely remove - I don't want to spend the same amount of time figuring this out again if I don't have to.

#NOTE 1: I've not had any issues related to these removals.

#NOTE 2: I am not running my system as an experiment, I need it for work and am not interested in any surprises; nor am I interested in "try this and see what happens".

My system:

  • O/S: Kubuntu 18.04 LTS
  • KDE: 5.12.9
  • KDE Frameworks: 5.44.0
  • Qt: 5.9.5
  • Kernel: 4.15.0-128-generic
  • CPU: i7-8750H
  • RAM: 8 GB

My question:

Now that Kubuntu 20.04 LTS is available, is there a way to upgrade only the existing components on my system to 20.04 LTS, or will an upgrade also re-install the previously removed components?

kde upgrade kubuntu 20.04

1 Answers

  1. Best Answer

    Now that Kubuntu 20.04 LTS is available, is there a way to upgrade only the existing components on my system to 20.04 LTS,

    That is what normally happens.

    or will an upgrade also re-install the previously removed components?

    As long as the software at the top of a branch does not require a specific component that component will not get installed during an upgrade.

    If you do decide to upgrade ... you made sure you have several backups and know how and are capable of restoring that backup. If that is the case you do an upgrade without the need to worry.

    I need it for work and am not interested in any surprises

    The best advice you will get though: do not upgrade (yet). You have until April 2023. An upgrade will go correctly except for that 1 time where you need it all to go smoothly. Then the weirdest things tend to happen ...

    There is plenty of time to plan ahead: change your current system such that you do not need to worry about an upgrade. Create a situation where all files you need, or changed have a backup on a 2nd disk or partition. I tend to get a new SSD and reinstall Ubuntu on that new disk and then mount my personal disk. Going back to the old setup means changing the SSD.

    I have modeled my personal system like a cloud instance: the main boot disk (an SDD) has changed files that are also on my HDD: the main components are my mysql config and databases, apache and nginx config files and websites. I also have a script to copy files over to the main disk so my HDD also supports me as a directly accessible backup (I basically have a mount point /discworld/ with in there a directory structure the same as / has but only the files I changed; so a /discworld/etc/apache2/sites-enabled/ and so on.

    Re-installing for me means I can always, without a shady of a doubt, nuke my SDD (that is my / and /home/) and install a new Ubuntu. 1 script executed later and I am back up and running. It takes me about 19 minutes from starting the install an being back online doing a full reinstall so not even an upgrade.

    Since my income depends on my system working as close to 100% I also have a second notebook that I use to mirror and once every so often test if it still works as a fallback. This 2nd notebook will automatically take over when the 1st one is out. In the next year you might also be able to invest in another notebook so you can mirror it too.

    Things I noticed myself: MySQL on Ubuntu 20.04 is a little more strict than on 18.04. You are no longer allowed to compare dates with a partial string. So if you used that kind of compares you will want to update your own software first before starting to upgrade. There is also a change in how the out of memory killer (oom killer) works: on 18.04 the whole offending service can get restarted by the OOM killer. In 20.04 the OOM killer tends to kill the offending thread and leave the service alone.

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