37

There's a way to safely try KDE on top of an Ubuntu installation, keeping the possibility to revert the changes in case I dislike how it runs?

dag729
  • 2,019

5 Answers5

28

The absolute safest way to do that is to install it on a separate partition, but that's probably more work than you need.
What I'd recommend is to install Kubuntu. I'm not sure if that's really what you meant when you said "KDE on top of an Ubuntu installation", but Kubuntu is little more than KDE+Ubuntu. Just do:

sudo apt-get install kubuntu-desktop Install Kubuntu

on any terminal window (it will install a ton of kde packages). By the end, you'll get prompted if you want to use gdm or kdm as login manager. It's OK to choose either one, but kdm will give you the full Kubuntu experience.

Next time you boot, just before logging in, choose KDE as your session manager. It will use the same $HOME and the same root folder, and thus you'll still have all the same programs installed, and their respective settings will be kept. I might be wrong, but I think only the settings stored under ~/.gnome2/ won't be loaded by KDE (they are gnome settings after all).

Finally, you don't really need to remove KDE after that. You can keep using gnome regularly, and never choose KDE again in the session manager. If, for some reason, you do want to really remove KDE (maybe you need to free up space), here's what you do:

sudo apt-get purge kubuntu-desktop

kubuntu-desktop is a dummy package (you'll notice the removal process will be quick), removing this package will make apt consider all of the kde packages as unnecessary (since they were brought along by this one), so just do:

sudo apt-get autoremove --purge

If you chose to keep gdm as your login manager, you can stop here. If you happened to choose kdm as your login manager back in the first step, you'll have to either reinstall gdm (it's technically already installed, so you can just reconfigure it if you know how) sudo apt-get install --reinstall gdm or reinstall kdm again sudo apt-get install kdm.

EDIT According to @AnwarShah the method above for removing Kubuntu doesn't actually work. I don't have an Ubuntu machine on which to test that right now, so I'll just provide an alternative method.

The command provided in this answer, should purge all traces of kde from your system. Before running it you should read all of the packages and make sure none of them had been previously installed by you! Make sure to remove the name of any packages you want to keep. (Also, I haven't read through all of those packages, so I can't garantee anything regarding the commands effectiveness.)

Alternatively, you could keept track of all packages installed when you install kubuntu-desktop, and then just do apt-get purge on these packages. This requires the forethought of copying the list of packages back when you installed kubuntu-desktop (and remembering where you saved it), but it's a little safer to do.

Community
  • 1
Malabarba
  • 10,196
  • 1
    Thank you so much: how do I keep track of every packages that come with kubuntu-desktop? – dag729 Oct 25 '10 at 00:21
  • 1
    @dag729: When you perform that first command, apt-get will list all packages that will get installed and ask for your confirmation. Copy them somewhere. – Malabarba Oct 25 '10 at 00:27
  • 1
    Usually, after "apt-get purge kubuntu-desktop", you can run "apt-get autoremove --purge" to remove everything else it pulled in. – Kees Cook Oct 25 '10 at 21:26
  • @kees: I thought about that, but wouldn't that remove kdm as well (thus causing issues on login)? – Malabarba Oct 25 '10 at 21:46
  • 1
    Perhaps, though gdm should still be there. If not, try following it with sudo apt-get install ubuntu-desktop to make sure it had everything Gnome needs. – Kees Cook Oct 26 '10 at 04:09
  • gdm will certainly still be there, but it will need to be reconfigured (or reinstalled) in case kdm is removed. I'll edit the answer with your method. – Malabarba Oct 26 '10 at 04:13
  • @BruceConnor.I test it and never works. Did you actually test it in your machine ?. It only removes kubuntu-desktop and after the second command nothing happens. I happens because kubuntu-desktop is a metapackage and in the case of metapackage, apt does not remove other packages which this metapackage brought. – Anwar May 14 '12 at 17:07
  • I'm not sure, I think I just trusted @KeesCook comment. =) From reading the manpage it seems like it should work. I'll add an extra method anyway. – Malabarba May 14 '12 at 17:17
  • @BruceConnor, Thanks that you notice it, But the problem with second method is it is dependent on the version of Ubuntu, (actually Kubuntu, since the default packages installed by kubuntu-desktop may change. Anyway, It will helps users. – Anwar May 15 '12 at 12:42
8

Just install it...

sudo apt-get install kubuntu-desktop Install Kubuntu

At login (after entering your username) you can select which one you want to boot (gnome/kde/xfce/...) so it's always possible to go back to gnome, even without rebooting.

Community
  • 1
sBlatt
  • 4,489
  • 4
    That works. Uninstalling the parts if you don't like it is not quite as straightforward, but can be done. – frabjous Oct 24 '10 at 22:38
  • 4
    I'd also add a new user just for testing KDE so it doesn't clutter up your existing $home with KDE configuration files. If you like KDE, fine, just use your normal user with the KDE session. If you don't like it, your profile hasn't been affected in any way. – Jonathon Oct 24 '10 at 23:42
  • @frabjous: Though if you mark everything kubuntu-desktop requires as an automatic (instead of manual) install, e.g. through aptitude, that should be much easier. –  Oct 25 '10 at 01:59
  • 1
    Creating a different user for testing purposes is in my opinion the best solution. – skalka Oct 25 '10 at 08:13
  • Uninstalling is not that easy. I tried it in natty, oneiric, and now in precise. It never works. Because dependents packages are never marks as automatically installed. This can give you a hint. apt-config dump. – Anwar May 14 '12 at 17:08
5

Maybe http://www.psychocats.net/ubuntu/kde can help you.

Just install Kubuntu Plasma Desktop system on your computer through the software center.

To uninstall it follow the instructions given here:

http://www.psychocats.net/ubuntu/puregnome

User
  • 4,526
1

Run it in a VM?

Or try a Live CD.

Cody Harlow
  • 1,452
  • 2
    Not an option, because I want to see how it works on the same conditions as gnome: I know how it is (I used kde back in karmic), but I want to try it with this new hardware and configurations. – dag729 Oct 24 '10 at 22:29
  • 2
    Ah, okay. Well a Live CD would work as well. – Cody Harlow Oct 24 '10 at 22:34
  • @Mitch "Run it in a VM or try a live CD" is definitely an answer to how to safely try a wide variety of software, including KDE. Answers don't become comments just by being short. If this were posted as a comment, I'd comment requesting that the author make it into an answer. – Eliah Kagan Aug 21 '12 at 17:53
-3

My choice (since refurbished systems are really cheap ~ $200) build a test-bench with these! I have several test-bench systems that I install on - before installing or upgrading critical systems. I've tried the live CD, but I prefer the test-bench.

Syborgia Alphas
  • 302