grub shows multiple kernel versions on startup

Question

I have Ubuntu 10.10 and after few updates the boot menu lists many kernel versions. How do I remove older versions?

Solution

1. Check for currently-installed kernels:

   $ dpkg --get-selections | grep linux-image
   linux-image-2.6.38-2-686-bigmem         install
   linux-image-2.6.32-5-686                install
   

2. Check what current kernel you are running:

   $ uname --all
   Linux debian 2.6.38-2-686-bigmem #1 SMP Thu Apr 7 06:05:53 UTC 2011 i686 GNU/Linux
   

3. Remove the kernel(s) you are displeased with, generally keeping the latest (and greatest).

   $ sudo apt-get remove linux-image-2.6.32-5-686
   

I think it's a good idea to keep at least two different versions though. However, I think this advice used to be more useful some time ago, because it seems the kernel gets more and more stable (I experience far less trouble than I used to), but maybe I'm lucky.