Cleaning up old kernel images on a Ubuntu machine is a quite annoying task. If you forget it and you have a separate /boot partition, then you will sooner or later run out of disk space. And then of course all your updates will fail.
Doing the clean up manually is, as mentioned, more than annoying and very tedious. But other smart people have spent some time and created a nice little one-liner that will get rid of old kernel versions. This command line will of course make sure that the currently running kernel is not removed. So it is very important to reboot after a kernel upgrade before you run this script!
And without further ado I present….
dpkg -l 'linux-*' | sed '/^ii/!d;/'"$(uname -r | sed "s/\(.*\)-\([^0-9]\+\)/\1/")"'/d;s/^[^ ]* [^ ]* \([^ ]*\).*/\1/;/[0-9]/!d' | xargs apt-get -y purge
Not a big deal but a sudo snuck into the xargs call. It is now removed and shouldn’t cause any trouble anymore.