How to delete old Kernels in Ubuntu; Remove old Kernels in Ubuntu Linux. On Ubuntu, first list the installed Kernels and then remove old Kernels via CLI/Terminal.
Remove Leftover Temp Files
Run the following command to delete leftover temporary files.
sudo rm -rv ${TMPDIR:-/var/tmp}/mkinitramfs-*
Step 1
Find out the current version of Linux kernel being used on the system and then list all installed kernels on the said system. To do so, run the following set of commands:
$ uname -sr
$ dpkg -l | grep linux-image | awk '{print$2}'
Step 2
Run the following command to list all the kernels excluding the booted kernel in the package database, and their status.
dpkg -l | tail -n +6 | grep -E 'linux-image-[0-9]+' | grep -Fv $(uname -r)
Remove Old Kernels
Once the Kernel to be removed is identified, run the following commands. For the example, we will remove Linux Kernel 4.2.0-15:
sudo update-initramfs -d -k 4.2.0-15-generic
sudo dpkg --purge linux-image-4.2.0-15-generic linux-image-extra-4.2.0-15-generic
sudo dpkg --purge linux-headers-4.2.0-15-generic
sudo dpkg --purge linux-headers-4.2.0-15
sudo apt-get -f install
$ sudo update-grub2
$ sudo reboot
How to Delete Old Kernels in Ubuntu originally posted on Source Digit – Latest Technology, Gadgets & Gizmos.