Remove old kernels on Linux

Display current kernel

  $ uname -r
  $ uname -mrs

On ubuntu

  • List all installed kernels
    $ dpkg --list | grep linux-image
  • Remove old kernels
    $ sudo apt-get autoremove

On RedHat, CentOS, and Fedora

  • list all installed kernels
    $ rpm -qa kernel
  • Remove old kernels
    # install yum utils
    $ dnf install yum-utils
    $ yum install yum-utils
    # Package-cleanup set count as how many old kernels you want left 
    $ package-cleanup --oldkernels --count=2
  • Make amount of installed kernels permanent
    Edit /etc/yum.conf or /etc/dnf/dnf.conf and set installonly_limit:
Written on April 27, 2017