Interrupted LINUX Upgrade to Ubuntu 14.04

My netbook was out of time, having Ubuntu 12.04. (Isn't that incredible old ?-)
I decided to "hop" to 14.04. The update-tool had invited me so often. Now I made the fatal click on "Upgrade".

During the upgrade I dared to open the system monitor, just to see how much space 12.04 had occupied on disk. The monitor came up and then froze, then the window decorations (title bar, borders) disappeared from all open windows. The installation still worked and showed progress.

Then I dared to restart the window manager (which is responsible for window decorations). In LINUX, when you press Alt-Ctl-F1, you get to a command-line terminal. "lightdm" is the Ubuntu window manager. I logged in as root, and then launched

service lightdm restart

This was the end of fun. Returning to my graphical screen, by pressing Alt-Ctl-F7, I gazed at a black screen. No installer dialog running, no activity going on. Broke that installation. It told me before that it must not be interrupted!

Rebooted. Black screen. Rebooted in rescue mode. Here I initialized the network to be able to manually continue with the interrupted installation. In such a situation you are dead without a second computer to browse the internet for help. Found the advice to do (as root)

dpkg --configure -a
apt-get update
apt-get upgrade

I repeated the two apt-get commands until all packages were installed correctly. Rebooted. But I had been in a kernel upgrade, so half of the new operating system was installed, and the old one was booting.

The command to install the new kernel is

apt-get dist-upgrade

After that everything was OK, apt-get told me that I am on the newest Ubuntu 14.04. Rebooted. There was the new grub 2. Worked. But again a black screen awaited me.

So now I suspected that my netbook is too weak for Ubuntu 14.04 that requires a good graphic card to do hardware acceleration for its compiz effects. I decided to switch to a lightweight desktop environment. Lubuntu has one. It is called LXDE. Pressing Alt-Ctl-F1 I got a terminal screen, logged in as root, and launched

apt-get remove ubuntu-desktop unity compiz

I used a lot more names in the remove command, to be found here on Ubuntu Forum, but I believe that the above command would have been sufficient to do it: remove Unity and compiz.

Then I installed the Lubuntu desktop environment (you can change them like a skin):

apt-get install lubuntu-desktop

Rebooted. Black screen. Now I was upset :-)
After all I began to look for error messages. The dmesg logging rarely is helpful. In this case I suspected that the window manager had a problem, and found out by

cat /var/log/lightdm/lightdm.log

There it said something about "no configuration found". I started to look for lightdm configuration files, and how I could disable my auto-login, so that I may see at least a login screen after booting. Found this in

vi /etc/lightdm/lightdm.conf

Changed the content of that file to

[SeatDefaults]
user-session=lubuntu
greeter-session=lightdm-gtk-greeter
autologin-user=

Did not touch any other line there. Rebooted. There was the login window! Logged in. Waited, long. There was my user session! Having my old desktop icons, the auto-starting Firefox loading all my tabs.

But none of the windows had a title bar, and none could be resized. Missing window decorations. So I need to find out what I have to reinstall to get rid of that. I already had done a

apt-get install --reinstall lightdm

Do I have to reinstall window decorations separately? Finally I returned to the login screen and switched the graphical environment in top-right corner from "GNOME" to "Lubuntu". Logged in again, there were the window decorations. For some reason Gnome does not provide window decorations here ... removed it by

apt-get remove --purge gnome-session-flashback

Lubuntu surprises were waiting: it has no graphical touchpad configuration! You can do it on command line using synclient, or you can

sudo apt-get install gsynaptics

After that you can call it immediately by typing gpointing-device-settings, or you can look for "Pointing Devices" menu item under "Preferences".

I wonder why tapping is not off by default. Who has so much feeling to NOT tap on some button by coincidence when moving the mouse by touchpad?

Next gotcha: how to get German keyboard? Lubuntu forums recommend a setxkbmap command in /etc/xdg/lxsession/Lubuntu/autostart, but it is simpler. Right-click on the "US" symbol in taskbar, click popup menu item "Properties", then uncheck the "Keep system layouts" checkbox. After that you can add another "Keyboard layout" in the left-side list. Move it to top to make it default.

Slowly I start to understand why Lubuntu is called lightweight. Because nobody cares about it. When clicking upon "Shutdown" nothing happens. Only doubleclick brings the shutdown dialog, but then twice :-) After a reboot my touchpad settings have been forgotten. Oh my! Finally I got that all as personal settings ... following I wrote in my

• $HOME/.config/lxsession/Lubuntu/autostart

@synclient MaxTapTime=0
@syncdaemon -d -t
@setxkbmap -layout "de,us"

As it is with LINUX, you do a lot of things, and finally it works but you don't know why, and you don't want to waste even more time by trying out what was the problem.
This was a quite long evening. Lubuntu is not for the impatient :-)

Here is a Blog of someone who managed to find out how to add launchers to the taskbar (Gnome "Panel").

Update

Hibernation does not work when closing the lid?

Before searching in Ubuntu forums and editing polkit configurations (policy kit), just open Preferences menu, go to Power Manager and check what is the action taken upon "Close lid". On my installation it was NOT "Suspend", so I had to set it manually. After that the computer really suspended when I closed the lid (although it takes some seconds).