If you have a huge amount of servers to monitor you might use auto-updates. this is quite fine for the most of us if you have the possibility to login sometimes and do some manual maintenance-tasks. But we all know this stress during the normal day and you might not be able to do this for all the machines. And we all know Murphy so you are likely to confront the situation that your boot partition shows a usage of 100 %.

Help is near!

Ok, but what now? Don't be frightened, this can be solved with a little bit of patience. But you should be careful and take your time! The following list is a step-by-step guide and lists you a short description and the command.

1. Update the repo-files.
   sudo apt-get update
2. Get the currently running kernel.
   uname -r
3. Get the list of installed kernels.
   dpkg -l linux-image-* | grep ii
4. Remove the unused kernels with the following command:
   rm /boot/*-3.19.0-25*
   The part 3.19.0-25 needs to be replaced. Information therefore is generated in step 3. You might keep one or two previous versions of your used kernel.
5. Try to reinstall the failed packages.
   apt-get -f install
6. Try to get some free space.
   apt-get autoremove
7. Check the free space.
   df -h
8. It might be necessary to repeat the steps 2 - 7 multiple times.

My conclusion

Since the most of my servers are not exposed to so many people (they are only used by my family) and they are not reachable from the internet I changed from automatic updates to manual ones and scheduled them old school via a reminder.