The way I have got an upgrade to 12.04 was not straight, since it started from 'rm -rf /*' accidentally invoked from Makefile with root permissions and incorrect variable I have set (do not touch Makefile being under root, it is very serious, sharp and edgy). Root partition was ruined in seconds. But usually I use several ones for different things - such are home, devel, docs, audio, video - everithing that I need to access time to time is on a separate partition, and they are usually not mounted. Perhaps something is not bad. But anyway, I have got a trouble number one.

I have two desktops, and second one still runs Oneiric, and even has an old CD/RW drive, USB ports, and internet connection. Not bad, but I had not suitable USB-flash nor robust and clean CD to burn bootable image. WTF? The problem number two.

Stuck? No.. Here on Oneiric is my DHCP server and TFTPD daemon, so the solution came very fast - netinstall mini.iso image, which is about 30 megabytes long. So I have configured netboot, booted installer onto ruined host and choosed guided partitioning to overwrite just old root with new one. Guided partitioning in mini.iso installer is capable to detect boot and root partitions that was previously in use, catch-up swap partition and friends, keeping others untouched. In my case only these 3 partitions reformatted.

After this I have decided to keep copy of that excellent mini.iso image in a boot partition as a separate menu entry (with some custom menu entry in grub.cfg, of course) to get possibility to boot installer without tftpd or dhcp configuration. For my future root drops.

What I have discovered?

LightDM is not for KDE, I suppose, and looks like a thing more closely to GNOME desktop, so my first request to install as much as many was reduced into a second request - to install a Kubuntu desktop only ("kdm and nothing else").

And indeed, it is faster than oneiric.