MySQL accesses files in various places on the file system, and usually this isn't something to worry about. For example, in a standard MySQL 5.5 installation on Ubuntu, the data goes in /var/lib/mysql, and the socket is a file in /var/run/mysqld. It puts configuration files in /etc, logs and binaries in various locations, and it even needs to access some operating system files such as /etc/hosts.allow.

This is all very well until you start trying to be clever and get MySQL to access other parts of the file system. After all, you can configure the location of data, log files, socket, and so on, so why shouldn't you use those settings to optimize your system? Unfortunately, on many modern Linux distributions, it's not that always easy.

Take Ubuntu, for example. Ubuntu comes with something called AppArmor, a kernel-integrated application security system that controls how applications can access the file system. This goes above …

I just updated to Ubuntu 11.10 “Oneiric” on one of my desktops and I ran into an issue with MariaDB.

It’s not an issue with MariaDB itself, more in how the MariaDB “Natty” .deb packages are configured. We haven’t released .deb packages for Ubuntu 11.10 “Oneiric”, but the Natty packages work fine, apart from this one configuration issue (and when we do release “Oneiric” packages, they will work out-of-the-box).

The main problem is that some things have moved around in “Oneiric” and Apparmor doesn’t like the MariaDB “Natty” Apparmor defaults file because it doesn’t account for some of the new destinations. Specifically, /var/run has been moved to /run (a discussion of the rationale behind the move can be found here). Other things have been moved too, but the /var/run to /run move is the one that is …