Archive for January, 2009

Dealing with AppArmor

January 19, 2009

Ordinary file-permissions are apparently not sufficient anymore. Ubuntu, and others, therefore uses AppArmor to associate programs with certain permission filters.

One such program is MySQL. When changing the datadir, it will most likely land somewhere outside the permissions granted by AppArmor and as a result fail. I would get errors (from /var/log/syslog) of the form:

Jan 19 00:41:12 asjo kernel: [262573.788599] type=1503 audit(1232322072.553:28): operation="inode_permission" requested_mask="r::" denied_mask="r::" fsuid=116 name="/vol/mysql/" pid=18262 profile="/usr/sbin/mysqld"

Others were having similar problems, as described in this thread among others.

This page solved my problem. Basically, you first put AppArmor in complain-mode regarding the specific program (in this case /usr/sbin/mysqld) by running this command:

sudo aa-complain /usr/sbin/mysqld

This will temporarily turn off the security and log the offending actions. Generate the offending actions by running the program:

sudo /etc/init.d/mysql start

Next you run

sudo aa-logprof

When asked if I wanted to “enable access to the profile repository” I answered L for ‘later’. Next it displays the offending action previously logged, at which point a allow it by answering A. At this point I am asked if I would like to save the changes. S for yes (save).

In order to re-enable security you simply run:

sudo aa-enforce /usr/sbin/mysqld


Pidgin unable to confirm certificate for

January 11, 2009

Today pidgin started displaying errors saying that it was unable to confirm the root certificate for It turns out to be a missing ‘pem’ file on my Ubuntu Intrepid Ibex (8.10) desktop.

It can easily be fixed by following this guide.