Clean-up unused Linux Kernels in Ubuntu

Original article by Mark McBride

At development I tend to keep more than one Virtual Machine sandboxes, normally Unix-based running on a Windows host (because of reasons), so from time to time I have to clean-up the garbage and maintain the user-disk cuota as low as possible to avoid eating up the VM drive.

The original author makes a pretty good explaination on the command sintaxis (basically list the kernels and strip-down recursively to usable name strings to uninstall them), so I'm just going to copy here the actual command:

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

Only one caveat: I removed the -y argument from the apt-get purge command to avoid eliminating automatically, instead you will get prompted to purge the listed kernels.  To check the used disk space:

$ du -h /boot --max-depth=0