small /boot partition for full system encryption becomes full after 7 updates and leads to failures

[C Filorux]

During installation with full system encryption, the Ubuntu installer creates an adequate /boot partition of around 100Mb.

However, after 10 updates to linux-image over the next few months, along with the running of update-initramfs the /boot partition becomes full. This causes further linux-image kernel updates to fail. Additionally, there are (undiagnosed) edge cases where improper handling of out-of-disk-space conditions in update-initramfs and/or update-grub this leads to additional failures. (I fixed a computer yesterday where /boot ran out of space, which caused grub to fail, which ended with "No Operating System" being displayed by the EFI BIOS. I previously fixed a system where a trivial upgrade failed on account of historical kernels in /boot - not a system failure, but a user interface disaster for Aunt Tilly.)

To prevent /boot from filling up, it would help if there was a limit to the number of historic kernel versions maintained. Older kernel versions are of interest to many developers, but having multiple revisions of kernels that are not used is not helpful for regular users.

A possible solution would be to "expire" automatically installed /boot updates which are not in active use. A wilder approach would be to move the large kernel files from /boot to some garbage collection point in /var ... or maybe not. Allocating more space to be wasted in /boot doesn't seem like a good idea.

The following workaround is published to remove all kernel versions except the current one:

dpkg --get-selections | \
  grep 'linux-image*' | \
  awk '{print $1}' | \
  egrep -v "linux-image-$(uname -r)|linux-image-generic" | \
  while read n
  do
    apt-get -y remove $n
  done

[Brad Figg (brad-figg)]

This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:

apport-collect 1222690

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Adam Niedling (krychek)]

No log files needed for this bug. I can confirm that this is a valid issue. The /boot partition is 228M in my case which is way too small compared to the size of a kernel image/header.

[Adam Niedling (krychek)]

I forgot to mention that my system is Ubuntu 13.04, I haven't tried to install 13.10 yet.