How to Clear a Full Boot Partition

<title>How to Clear a Full Boot Partition</title>
​​​Ubuntu usually creates a separate /boot partition for storing Linux kernels. This isolates the kernels from the rest of the operating system, which helps make the system more stable. However, as it is usually a small partition (> 200 MB), it can fill up with old kernels. While keeping a couple old kernels around can be advisable, so as to be able to roll back to old kernels if a new one proves unstable (an unusual occurrence), it is not necessary to keep more than one or two.

A user will usually notice they are out of space in **/boot** only after it is causing problems. If a new kernel tries to install without enough space, the installation will fail. If the system is then rebooted and it tries to use the new kernel, it will have a kernel panic. Sometimes it will be more graceful and simply cause dependency problems, which cripples the functionality of apt-get.

​Here are some tricks to solve this problem:
  -​​ If you've run into a kernel panic at boot time, select the //Advanced Boot// option from the Grub menu and select an older kernel version to boot from (do not use recovery mode). You may have to try a few before you find one that works.
  - When you have a functioning terminal to use, check the Linux kernel version you are currently running. **DO NOT REMOVE THIS KERNEL**.
    * <code>uname -r</code> 
  - Check which old kernels you have
    *  <code>ls /boot</code>
  - Force the removal of one or two old kernels (//update with the version of the kernel you wish to remove//)
    * <code>sudo dpkg --force-all -P linux-image-3.13.0-32-generic</code> 
    * ​You will probably need to use the same command to delete the ''linux-image-extra'' version of the corresponding kernels to fix dependency problems.
  - ​Once you are certain you have enough free space fix any existing dependency problems. 
    * <code>sudo apt-get install -f</code>
    * //Make sure this command does not try to reinstall the kernels you just removed.// If it does, you need to remove the ''linux-image-extra'' packages for those kernels (there may be other such dependencies, check online).
  - Once you've got any dependency issues resolved, run **''sudo apt-get autoremove''** to remove the other old kernels.
    * As an alternative to ''autoremove'', you try the following command, though using a low-level utility such as dpkg is not necessarily recommended. It will remove all kernels except the one currently running.
      * <WRAP prewrap><code>sudo apt-get purge $(dpkg -l linux-{image,headers}-"[0-9]*" | awk '/ii/{print $2}' | grep -ve "$(uname -r | sed -r 's/-[a-z]+//)")</code></WRAP>
  - Odds are, there's a new kernel waiting to be installed. Once you've done all this to clear out your ''/boot'' partition, run **''apt-get update''** and **''apt-get upgrade''** to update your system (including any new kernels).