[CentOS] hacking grub to control number of retained kernels.

Sat Sep 3 15:18:09 UTC 2016
Liam O'Toole <liam.p.otoole at gmail.com>

On 2016-09-03, Fred Smith
<fredex at fcshome.stoneham.ma.us> wrote:
> I've recently had this problem on two C7 systems, wherein when doing
> "yum update", I get a warning about /boot being low on space.
> both systems were installed using the partition size recommended by
> Anaconda, right now "df -h" shows /boot as 494M, with 79M free.
> I don't store unrelated crap on /boot, I assume that yum and/or grub
> will manage it for me. So, why, after over a year, is it running low
> on space on two different systems?
> Is there some location in /boot where junk piles up, but shouldn't,
> that I have to know about so I can clean it out?
> I see EIGHT initramfs files in /boot, two per kernel, same name but
> one has a kdump just before the .img suffix. do I need those for old
> kernels that I may or may not ever boot? (they're 30 to 50 MB each).
> For the moment I've edited /etc/grub.conf and changed
> installonly_limit from 4 to 3. (related question: do I need to
> manually remove the oldest kernel, having done this, or will yum/grub
> clean it up the next time there's a kernel to install?)
> thanks!
> Fred

I recommend the package-cleanup command from the yum-utils package. See
the '--oldkernels' option in particular; it will remove obsolete
kernels, i.e., those which are no longer installable from your yum