Uninstall Unused Old Kernels on Linux

those of them who are used to web interface, like Webmin, will delete their old kernels but won’t be able to proceed with the installation of a new Linux kernel. Interestingly enough, great Webmin just does not show all installed kernels. Some kind of a bug, I guess.

Well, your solution is to open the terminal and find out how many kernels are there anyways. So you need to type up:
rpm -q kernel | sort

Then you need to find out which kernel is the default one on your machine. So invoke the following command on your terminal:

uname -r

Then while whistling some funny melody, start uninstalling one by one all useless kernels. Here is the command:

rpm -e kernel(and its version)

Don’t forget to reboot. The alert would not bother you anymore.

Note: Please, be careful with uninstallation. Don’t erase all kernels, leave at least a couple of them in case a new update is gonna cause you problems. In that case, you will just switch back to the old kernel and wait for another kernel update.