Ubuntu Cleanup: How to Remove All Unused Linux Kernel Headers, Images and Modules

First do upgrade to the latest kernel and reboot with the new kernel, make sure everything works!

$ uname -a
Linux MDS 3.2.0-54-generic #82-Ubuntu SMP Tue Sep 10 20:09:12 UTC 2013 i686 i686 i386 GNU/Linux

Then check all the linux kernel installed:

$ dpkg -l 'linux-*'
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name                                      Version                                   Description
+++-=========================================-=========================================-==================================================================================================
un  linux-doc-3.2.0                                                               (no description available)
ii  linux-firmware                            1.79.6                                    Firmware for Linux kernel drivers
ii  linux-generic                             3.2.0.54.64                               Complete Generic Linux kernel
un  linux-headers                                                                 (no description available)
un  linux-headers-3                                                               (no description available)
un  linux-headers-3.0                                                             (no description available)
un  linux-headers-3.2.0-23                                                        (no description available)
un  linux-headers-3.2.0-23-generic                                                (no description available)
ii  linux-headers-3.2.0-52                    3.2.0-52.78                               Header files related to Linux kernel version 3.2.0
ii  linux-headers-3.2.0-52-generic            3.2.0-52.78                               Linux kernel headers for version 3.2.0 on 32 bit x86 SMP
ii  linux-headers-3.2.0-54                    3.2.0-54.82                               Header files related to Linux kernel version 3.2.0
ii  linux-headers-3.2.0-54-generic            3.2.0-54.82                               Linux kernel headers for version 3.2.0 on 32 bit x86 SMP
ii  linux-headers-generic                     3.2.0.54.64                               Generic Linux kernel headers
un  linux-image                                                                   (no description available)
un  linux-image-3.0                                                               (no description available)
ii  linux-image-3.2.0-52-generic              3.2.0-52.78                               Linux kernel image for version 3.2.0 on 32 bit x86 SMP
ii  linux-image-3.2.0-54-generic              3.2.0-54.82                               Linux kernel image for version 3.2.0 on 32 bit x86 SMP
ii  linux-image-generic                       3.2.0.54.64                               Generic Linux kernel image
un  linux-initramfs-tool                                                          (no description available)
un  linux-kernel-headers                                                          (no description available)
un  linux-kernel-log-daemon                                                       (no description available)
ii  linux-libc-dev                            3.2.0-54.82                               Linux Kernel Headers for development
un  linux-restricted-common                                                       (no description available)
ii  linux-sound-base                          1.0.25+dfsg-0ubuntu1.1                    base package for ALSA and OSS sound systems
un  linux-source-3.2.0                                                            (no description available)
un  linux-tools                                                                   (no description available)

List all old kernels:

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

linux-headers-3.2.0-52
linux-headers-3.2.0-52-generic
linux-image-3.2.0-52-generic

Run this command to clean the old kernel:

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

Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED:
  linux-headers-3.2.0-52* linux-headers-3.2.0-52-generic* linux-image-3.2.0-52-generic*
0 upgraded, 0 newly installed, 3 to remove and 0 not upgraded.
After this operation, 181 MB disk space will be freed.
(Reading database ... 152425 files and directories currently installed.)
Removing linux-headers-3.2.0-52-generic ...
Removing linux-headers-3.2.0-52 ...
Removing linux-image-3.2.0-52-generic ...
Examining /etc/kernel/postrm.d .
run-parts: executing /etc/kernel/postrm.d/initramfs-tools 3.2.0-52-generic /boot/vmlinuz-3.2.0-52-generic
update-initramfs: Deleting /boot/initrd.img-3.2.0-52-generic
run-parts: executing /etc/kernel/postrm.d/zz-update-grub 3.2.0-52-generic /boot/vmlinuz-3.2.0-52-generic
Generating grub.cfg ...
Found linux image: /boot/vmlinuz-3.2.0-54-generic
Found initrd image: /boot/initrd.img-3.2.0-54-generic
Found memtest86+ image: /boot/memtest86+.bin
done
The link /vmlinuz.old is a damaged link
Removing symbolic link vmlinuz.old
 you may need to re-run your boot loader[grub]
The link /initrd.img.old is a damaged link
Removing symbolic link initrd.img.old
 you may need to re-run your boot loader[grub]
Purging configuration files for linux-image-3.2.0-52-generic ...
Examining /etc/kernel/postrm.d .
run-parts: executing /etc/kernel/postrm.d/initramfs-tools 3.2.0-52-generic /boot/vmlinuz-3.2.0-52-generic
run-parts: executing /etc/kernel/postrm.d/zz-update-grub 3.2.0-52-generic /boot/vmlinuz-3.2.0-52-generic

This will generate a new GRUB menu, and when you reboot, you’ll see only the current kernel is listed.