During christmas, I have been working getting the next version of +Debian Edu / Skolelinux ready +for release. The initial problem I looke 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.
+