I have two Linux systems as described below:
Ubuntu Linux 12.04.1
Kernel = Linux 3.2.0-57-generic on x86_64
Ubuntu Linux 12.04
Kernel = Linux 3.2.0-34-generic on x86_64
Server #1 has been getting regular kernel and package updates over quite some time.
Server #2 has also been getting regular package updates, EXCEPT the kernel is hung at 3.2.0-34.
First of all, I do not notice any problem with the down level kernel system on Server #2. Therefore, I haven't bother to look into it, but feel at some point it should be fixed.
This may be a clue for someone to help me understand why, and suggest a cure. The server ran out of space on the partition where the kernel is stored. I noticed that there were many kernel files (old ones). The old files were taking up too much space. Therefore, I booted the machine. At Grub, I choose an older kernel to boot to since the machine was out of space, and the latest kernel was screwed up would not boot. Once I got the system up, I deleted all the old kernel files, including the newest one that failed the upgrade. Now, I am booting to Linux 3.2.0-34-generic ever since. The other system has moved up to "57".
How do I flush update process to remove whatever that is not letting the Ubuntu upgrade process detect the kernel is out-of-date?