So much has happened since I last blogged here. I passed my last exam and turned in my thesis … and since some people asked: yep, I passed and may now call myself “Diplom-Informatikerin” 
Right now I’m busy applying for jobs, finishing some final things for university and working on delicious2safari, so stay tuned
I think that I shall never see A graph more lovely than a tree. A tree whose crucial property Is loop-free connectivity. A tree which must be sure to span. So packets can reach every LAN. First the Root must be selected By ID it is elected. Least cost paths from Root are traced In the tree these paths are placed. A mesh is made by folks like me Then bridges find a spanning tree.
from R. Perlman: An Algorithm for Distributed Computation of a Spanning Tree in an Extended LAN (PDF)
On that note: I passed my computer networks + mobile computing exam today … only two more exams and the diploma thesis left. Yay!
This is our new student lab, in beta-testing since Friday. The machines run Windows XP and Ubuntu Linux.
Installation of Ubuntu is fully-automated through Debian installer preseeding. Its partitioner is replaced with a custom udeb that provides formatting for the Linux partitions, while preserving the complex partitioning scheme that Windows/Norton Ghost needs.
Updates and patches get distributed using a custom toolkit written in Python (originally designed by Fabi for RedHat-based systems). It consists of an NFS mount with directories for different classes of machines, and a script (run by cron or on-demand) that checks for new updates to the machine classes a system belongs to. Updates are represented by numbered symbolic links to files, tars, text files with package names to be installed through apt, debs, patches and shell scripts. The on-demand updating and other administrative tasks are initiated through SSH Forced Commands. The postinstall process is also done using the same system, through rc-style numbered scripts.
Each machine has a separate installation partition, containing a netboot kernel, initrd, and the machines’s boot loader (Grub) installed into its boot sector along with the associated configuration files. The installation partition is distributed by Norton Ghost (which is used by the Windows guys anyway to distribute their images), and has the “bootable” flag set. This enables Ghost to install Windows and reboot it multiple times by simply removing the flag and restoring it after installation is complete. By providing a Grub configuration file that will boot into the installation kernel with appropriate kernel parameters for preseeding, any machine running Linux can be re-installed at any time by simply mounting the installation partition and copying the special installation configuration over the normal menu.lst (of course it will have to be reset before the installation reboots for the first time, or we’ll end up in an endless cycle of base installs).
I’ll probably have more to say on this later, but here’s a random collection of “lessons learned” while setting up this lab:
Die Folien zum heutigen inf.misc Vortrag Remote Tools gibt’s ab sofort als PDF zum runterladen.
It’s been rather quiet here for the last weeks since I’ve been very busy taking exams, and helping with orientation for the new students. I also revised the computer labs “manual” each new student gets, and developed a new default configuration for newly created Linux accounts. The new configuration provides better performance on older machines and is more easy to use. It uses Xfce as the desktop manager, Thunderbird for email, and Firefox for web browsing. Hopefully this will make Linux a little easier to use for beginners, and faster on our older lab machines …
Anyway, I still have one more exam to take this week, and hopefully after that I’ll have more time for “the rest of my life” again 
