Comment 4 for bug 690911

I regularly install security updates. As I've now been running 12.04 for over a year, I have now 24 old kernel versions (in series 3.2.x) taking up to 1,7 gigabytes of disk space.

I did now run the spell
dpkg -l 'linux-*' | sed '/^ii/!d;/'"$(uname -r | sed "s/\(.*\)-\([^0-9]\+\)/\1/")"'/d;s/^[^ ]* [^ ]* \([^ ]*\).*/\1/;/[0-9]/!d' | xargs sudo apt-get -y purge

..but I hope Ubuntu would have some built-in mechanism to remove old kernels, since regular users are not likely to do this kind of maintenance manually.