Safely Remove / Delete Old Linux Kernel from a Linux Server

We have four different versions of Linux kernel installed by the yum command under CentOS Linux. Currently, I am using only latest version 2.6.18-53.1.4.el5. What is proper and suggested method to remove old kernels from a CemtOS / Debian Linux server?

Most Linux distro keeps old kernel files so that you can revert in case of emergency pop up due to hardware or software incompatibility issues. A kernel is nothing but a set of files on Linux box. Following is the suggested way to remove old kernels safely on Linux based system.

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Step # 1: Find the current kernel version

uname -r
Sample outputs:

2.6.18-53.1.4.el5

Step #2: List all installed kernels

Use the rpm command or dpkg command on Linux:
# rpm -q kernel
Sample outputs (from RPM based distro such as CentOS/RHEL):

kernel-2.6.12-1.el5
kernel-2.6.18-17.el5
kernel-2.6.18-53.el5
kernel-2.6.18-53.1.4.el5

Debian / Ubuntu Linux user, enter:
$ dpkg --list 'linux-image*'
Sample outputs:

Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Installed/Config-f/Unpacked/Failed-cfg/Half-inst/t-aWait/T-pend
|/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err: uppercase=bad)
||/ Name                          Version                       Description
+++-=============================-=============================-==========================================================================
ii  linux-image                   2.6.22.14.21                  Generic Linux kernel image.
un  linux-image-2.6                                       (no description available)
rc  linux-image-2.6.20-15-generic 2.6.20-15.27                  Linux kernel image for version 2.6.20 on x86/x86_64
ii  linux-image-2.6.20-16-generic 2.6.20-16.32                  Linux kernel image for version 2.6.20 on x86/x86_64
ii  linux-image-2.6.22-14-generic 2.6.22-14.47                  Linux kernel image for version 2.6.22 on x86/x86_64
ii  linux-image-generic           2.6.22.14.21                  Generic Linux kernel image

Step #3: Remove all old kernels

WARNING! These examples may result into unstable system if not executed with care. Do not remove the kernel the system is currently running.

Choose which kernel you want to uninstall from the list of those installed. Type the following command to remove the kernel package under RHEL / CentOS / Fedora Linux:
# rpm -e kernel-2.6.12-1.el5
Type the following command to remove the kernel package under Debian / Ubuntu Linux:
$ sudo apt-get remove linux-image-2.6.22-14-generic
Please note that on newer system all obsolete kernels and headers should automatically be flagged as no more needed, and thus can be purged with the following single command:
$ sudo apt-get --purge autoremove
Sample outputs:

Fig.01: Deleting all older kernels on an Ubuntu server

Fig.01: Deleting all older kernels on an Ubuntu server

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29 comments… add one
  • blink4blog Jan 8, 2008 @ 11:53

    Hi there,

    Does these commands work for SUSE 10.3? I tried

    # rpm -q kernel

    does not return the list, but message says:

    package kernel is not installed

    • suranjan Sep 25, 2010 @ 12:02

      you should write like
      rpm -e kernel “packagename”.
      first check which do you want to uninstall by writing uname -r.

  • Casper Pedersen Jan 8, 2008 @ 12:16

    SuSE does not leave old kernels behind (as long as nothing have been modified), it updates the kernel. Where as RedHat does an install.

  • Nilesh Jan 9, 2008 @ 1:04

    hey the method is wrong for Fedora.

    $ sudo apt-get remove linux-image-2.6.22-14-generic

    doesn’t usually work as default packman in Fedora is yum and there is no package like linux-image.

    it simply called kernel in Fedora.

  • 🐧 nixCraft Jan 9, 2008 @ 9:48

    Nilesh,

    apt-get only works on Debian / Ubuntu and other Debian based distro. For fedora, use yum or rpm command.

  • Nilesh Jan 9, 2008 @ 12:25

    vivek, first you in the post said that remove old kernel using ur cmd on Fedora. Now you updated it and u r tellin
    me now ?? lol. i know that’s why i suggested. :)

  • 🐧 nixCraft Jan 9, 2008 @ 14:32

    Nilesh, yup, it was a typo. Thanks for the heads up and your post. :)

  • reckless2k2 Jan 9, 2008 @ 14:49

    I remove old kernels in CentOS using yum. I usually check the current running kernel:

    #uname -r

    query the list of kernels:

    #rpm -qa kernel*

    and then remove older kernels using yum:

    #yum remove kernel-x

  • Sadicote Dec 27, 2008 @ 10:02

    Hi, for your kind information:

    sade@sade-desktop:~$ dpkg --list 'linux-image*'
    Desired=Unknown/Install/Remove/Purge/Hold
    | Status=Not/Inst/Cfg-files/Unpacked/Failed-cfg/Half-inst/trig-aWait/Trig-pend
    |/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err: uppercase=bad)
    ||/ Name           Version        Description
    +++-==============-==============-============================================
    un  linux-image             (no description available)
    un  linux-image-2.          (no description available)
    ii  linux-image-2. 2.6.27-7.16    Linux kernel image for version 2.6.27 on x86
    ii  linux-image-2. 2.6.27-9.19    Linux kernel image for version 2.6.27 on x86
    ii  linux-image-ge 2.6.27.9.13    Generic Linux kernel image
    sade@sade-desktop:~$ sudo apt-get remove linux-image-2. 2.6.27-7.16
    [sudo] password for sade: 
    Reading package lists... Done
    Building dependency tree       
    Reading state information... Done
    E: Couldn't find package linux-image-2.
    sade@sade-desktop:~$ sudo apt-get remove linux-image 2.6.27-7.16
    Reading package lists... Done
    Building dependency tree       
    Reading state information... Done
    Package linux-image is not installed, so not removed
    E: Couldn't find package 2.6.27-7.16
    sade@sade-desktop:~$
  • Chris Mar 14, 2009 @ 5:55

    Hi Vivek, keep up the great work!

    I just removed all my kernels on accident. Now when I boot from DVD I do not have /dev/cdrom, nor /dev/scdX, and I cannot get to kernel rpm packages.
    I also cannot chroot /mnt/sysimage
    The error is: cannot run command ‘/bin/sh’: No such file or directory

    Please suggest how to restore this system.
    Best regards,
    Chris

  • Chris Mar 14, 2009 @ 5:56

    PS – I booted from DVD with: linux rescue

  • Shibu Jan 27, 2010 @ 12:26

    I used sudo apt-get remove linux-image-2.6.28-11-generic and removed the old kernel. But the configuration files are not removed. It shows
    rc linux-image-2. 2.6.28-11.42 Linux kernel image for version 2.6.28 on x86
    Is there any way to clean up the configuration files also of the removed kernel?

  • dude May 11, 2010 @ 10:21

    None of this worked for 9.04, 9.10 or 10.04.
    Guess i start using something else then Ubuntu since they allways have to rename functions

  • excogitation Nov 3, 2010 @ 18:22

    @Shibu: dpkg –purge linux-image-2. 2.6.28-11.42

  • Ahmad Oct 1, 2011 @ 15:57

    This command removes all the old kernels:

    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
    
    • Simon May 7, 2013 @ 21:24

      Ahmad – thanks for this command, brilliant!

    • DanielS May 16, 2013 @ 23:07

      This works a treat! Thanks a ton!
      I really do need to teach myself some sed love…

    • Piffo Apr 9, 2015 @ 5:24

      A wonderful command. However in my situation some kernels were “not empty so not removed” which means I have still ten old kernels taking 150 Mb a piece. I will keep looking for a solution and get back to you all if I find it.

  • Yousaf Oct 14, 2011 @ 19:04

    i have the following problem

    {
    [root@yousaf Yousaf]# uname
    Linux
    [root@yousaf Yousaf]# uname -r
    2.6.33.3-85.fc13.i686
    [root@yousaf Yousaf]# rpm -q kernel
    kernel-2.6.33.3-85.fc13.i686
    [root@yousaf Yousaf]# rpm -e kernel-2.6.33.-85.fc13.i686
    error: package kernel-2.6.33.-85.fc13.i686 is not installed
    [root@yousaf Yousaf]# sudo rpm -e kernel-2.6.33.-85.fc13.i686
    error: package kernel-2.6.33.-85.fc13.i686 is not installed
    }

    What i do some problem i have face in many software when i want to remove that

    • Nas Iwuede Dec 13, 2011 @ 14:37

      use this cmd
      rpm -r kernel-2.6.33.3-85.fc13.i686
      or
      yum remove kernel-2.6.33.3-85.fc13.i686

      besure to install previous version of kernel

  • thiyagi Nov 14, 2011 @ 9:25

    Nice,,

  • Alexandr Feb 22, 2013 @ 10:42

    yum list installed | grep kernel-*
    yum remove (or erase) kernel-*

    then check your all rest kernels…

  • Kenny Jun 3, 2013 @ 6:41

    I think this is exactly what I’m looking for. However, I have the problem that when I try:

    sudo apt-get remove linux-image-3.5.0-17-generic

    I get:

    The following packages have unmet dependencies:
    linux-image-extra-3.5.0-17-generic : Depends: linux-image-3.5.0-17-generic but it is not going to be installed
    linux-image-extra-3.5.0-32-generic : Depends: linux-image-3.5.0-32-generic but it is not going to be installed
    linux-image-generic : Depends: linux-image-3.5.0-32-generic but it is not going to be installed
    E: Unmet dependencies. Try ‘apt-get -f install’ with no packages (or specify a solution).

    Of course, sudo apt-get -f install fails with the following message:

    dpkg: error processing /var/cache/apt/archives/linux-image-3.5.0-32-generic_3.5.0-32.53_amd64.deb (–unpack):
    cannot copy extracted data for ‘./boot/System.map-3.5.0-32-generic’ to ‘/boot/System.map-3.5.0-32-generic.dpkg-new’: failed to write (No space left on device)
    No apport report written because the error message indicates a disk full error

    Apparently my boot partition is too full for me to run sudo apt-get -f install, which I need to run in order to clean up my boot partition! Any thoughts?

    • LaVaughn May 19, 2015 @ 14:08

      I am having the same issue on my Ubuntu 12.04 LTS machine. Any suggestions or help is appreciated.

      • John Ward Sep 22, 2015 @ 12:32

        Try this. Check what you are currently running:
        $ uname -r
        3.13.0-53-generic

        Go into root shell:
        $ sudo -s

        List some of the init files in the /boot directory; cd into /boot and run:
        # ls init*

        initrd.img-3.13.0-45-generic initrd.img-3.13.0-46-generic initrd.img-3.13.0-48-generic initrd.img-3.13.0-49-generic initrd.img-3.13.0-51-generic initrd.img-3.13.0-52-generic initrd.img-3.13.0-53-generic

        Clear some of the files you don’t need, without actually removing them:
        # echo “” > initrd.img-3.13.0-45-generic
        # echo “” > initrd.img-3.13.0-46-generic
        # echo “” > initrd.img-3.13.0-48-generic
        # echo “” > initrd.img-3.13.0-49-generic

        Exit the root shell. You should now have space to run:
        $ sudo apt-get -f install
        $ sudo apt-get autoremove

        • Juri Apr 13, 2016 @ 18:04

          Thanks a lot! That worked for me!

  • Alexandr Jun 14, 2013 @ 9:03

    For Oracle Linux you have to do:
    rpm -qa kernel-uek
    rpm -e kernel-uek-

    Works only for Oracle kernels!

  • PixEye Feb 25, 2014 @ 9:56

    Hi, I wrote a shell script for GNU/Linux Debian base systems such as Ubuntu boxes.
    You can find it at github:
    https://github.com/PixEye/PixShellScripts/blob/master/clean-old-kernels.sh
    Hope this helps.

  • Dixie Oct 13, 2016 @ 12:13

    Why is it so hard to remove it.
    Why are they been kept (more than 1 for stability reasons) for so long?
    Why is linux so bad at everything?

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