up2date installed a new kernel but did not remove earlier.
 

My first session with up2date tempted me to start with the kernel updating. I did that and it installed the new version of the kernel. Old and new both are (ntpl) (What is this? I do not know). The two kernels differ in 2.x.y.zzzz 2.x.y.aaaa.

I am surprised to see that in the bootloader now new kernel is added (previously I had two options DOS and Kernel 2.x.y.zzzz (ntpl) now the third option Kernel 2.x.y.aaaa is added.)

Do I really need to keep the old kernel? If yes why? If no how should I remove the old kernel.

Thanks in advance

Dinesh

Let's say you install a new kernel, and it doesn't work with your system. If you still had the old kernel installed, you could just hit the power button and reboot to it. If you didn't, you would be in trouble.

If the new kernel is working fine, you don't really need the old one anymore. It doesn't hurt to leave it, though. To remove it, you can use "rpm -e kernel-version_numbers". If you have a custom kernel, or don't want to trust the package-manager, you would need to delete three files (initrd-version_numbers, System.map-version_numbers, and vmlinuz-version_numbers), edit your /etc/grub/grub.conf to remove the entry, and delete /usr/lib/modules/version_numbers. After that, the old kernel is gone.