Ubuntu devs fix some showstopper bugs

By Sam Varghese
Thursday, 12 November 2009 01:35

Opinion and Analysis

The Ubuntu development team has identified a couple of problems which could have been behind complaints from a small subset of users who found the upgrade from older releases to Karmic Koala (version 9.10) a difficult process.


The complaints were highlighted by the British technology publication, The Register, and included blank and flickering screens, inability to recognise hard drives, defaulting to the 2.6.28 kernel, and failure to get encryption running.

Karmic Koala was released on October 29, just two weeks ago.

Mark Shuttleworth, the head of Canonical, the parent company of Ubuntu, pointed me to a web page where the developers have outlined details of the video problem and fixes for the same.

He said he had seen no sign that there were any major issues with hard drives, defaulting to older kernels or encryption. "I've no doubt there are regressions but none that have yet crossed the threshold to 'widespread consequence'," he added.

The blank and flickering screens on boot have been identified as being caused by a missing kernel module and this was experienced by users who had computers with video cards that use nvidia chips.

In their description of the bug, the developers said that the nvidia kernel module could be missing because it failed to build due to the combination of kernel, driver and hardware; at this point, the hardware administration tool, Jockey, was supposed to inform the user of the problem.

However a bug in Jockey could be preventing this from happening; fixes for this bug have already been committed.

Another case where the nvidia kernel module could be missing was because of the speed of the boot process - which, as the developers pointed out, was ironically one of the main improvements in Karmic Koala.

When a new kernel is installed, dynamic kernel module support is expected to rebuild the nvidia module during the boot process. The speed of the boot process could be resulting in failure to rebuild this module.

The best fix for this was identified as a serialisation of the drive update process to ensure that the nvidia kernel module was always built before the graphical login interface came up.

As a short-term fix, it has been proposed to add a job in the boot sequence to make the login interface delay showing up until the dynamic kernel module support process is completed.

There were two other cases identified which could cause the same issue - lack of a nvidia module for specialised kernels and lack of the module due missing or broken system pieces.

The development team has also identified a number of improvements for proprietary video drivers in x.org. the windowing system used by all GNU/Linux distributions. Most of these will be implemented for the next release, Lucid Lynx, or 10.04, which is due in April 2010.