How to remove old Linux kernel images from /boot

For RedHat based OS

e.g RHEL or CentOS

Install yum-utils

yum -y install yum-utils

Check current running kernel version

rpm -q kernel

Remove old kernels, but leave the 2 latest ones.

package-cleanup --oldkernels --count=2

Edit /etc/yum.conf and set:

installonly_limit=2

This will delete old kernels automatically but leave the latest two next time you perform a yum update

For Debian based OS

e.g Ubuntu

apt-get -f autoremove
update-grub

If that doesn’t work, you may need to manually remove files from /boot using rm. Then run update-grub after.

You can always check what kernel is currently loaded by running uname -a.