Petter Reinholdtsen

During christmas, I have been working getting the next version of Debian Edu / Skolelinux ready for release. The initial problem I looked at was particularly interesting.

The installer would hang at the end when it was doing it post-installation configuration, and whatevery I did to try to find the cause and fix it always worked while I tested it, but never when I integrated it into the installer and ran the installation from scratch. I would try to restart processes, close file descriptors, remove or create files, and the installer would always unblock and wrap up its tasks.

Eventually the cause was found. The kernel was simply running out of entropy, causing the Kerberos setup to hang waiting for more. Pressing keys was adding entropy to the kernel, and thus all my tries to fix the problem worked not because what I was typing to fix it, but because I was typing.

The fix I implemented was to add a background process looking at the level of entropy in the kernel (by checking /proc/sys/kernel/random/entropy_avail), and if it was too small, the installer will flush the kernel file buffers and do 'find /' to generate some disk IO. Disk IO generate entropy in the kernel, and is one of the few things that can be initated from within the system to generate entropy.

The fix is in beta1 of the Debian Edu/Squeeze version, and we welcome more testers and developers. We plan to release beta2 this weekend.

I am happy to announce that today we managed to wrap up and publish the second beta version of Debian Edu / Skolelinux. If you want to test a LDAP backed Kerberos server with out of the box PXE configuration for running diskless machines and installing new machines, check it out. If you need a software solution for your school, check it out too. The full announcement is available on the project announcement list.

In the Squeeze version of Debian Edu / Skolelinux soon to be released, users of the system will get their default browser start page set from LDAP, allowing the system administrator to point all users to the school web page by updating one setting in LDAP. In addition to setting the default start page when a machine boots, users are shown the same page as a welcome page when they log in for the first time.

The LDAP object dc=skole,dc=skolelinux,dc=no have an attribute labeledURI with "http://www/ LDAP for Debian Edu/Skolelinux" as the default content. By changing this value to another URL, all users get to see the page behind this new URL.

An easy way to update it is by using the ldapvi tool. It can be called as "ldapvi -ZD '(cn=admin)'' to update LDAP with the new setting.

We have written the code to adjust the default start page and show the welcome page, and I wonder if there is an easier way to do this from within Iceweasel instead.