[CentOS] Centos 5.5, not booting latest kernel but older one instead

[Keith Roberts]

On Mon, 30 Aug 2010, fred smith wrote:

> To: centos at centos.org
> From: fred smith <fredex at fcshome.stoneham.ma.us>
> Subject: [CentOS] Centos 5.5, not booting latest kernel but older one instead
> 
> I've been going along not noticing things happening right under my nose.
> so imagine my surprise when I discovered last night that my Centos 5 box
> has installed multiple new kernels over the last few months, as updates
> come out, and IT IS NOT BOOTING THE NEWST ONE.
>
> grub.conf says to boot kernel 0, and 0 is the newest one. but the one it
> actually boots is 6 or 8 down the list (clearly I've not been keeping
> things cleaned up, either).
>
> Below is some info that shows the problem. Can anyone here provide
> helpful suggestions on (1) why it is doing this, and more importantly (2)
> how I can make it stop?
>
> Thanks!
>
> uname reports:  2.6.18-164.15.1.el5PAE #1 SMP Wed Mar 17 12:14:29 EDT 2010 i686 athlon i386 GNU/Linux
>
> while /etc/grub.conf contains:

/etc/grub.conf ??

don't you mean /boot/grub/grub.conf ?

> # grub.conf generated by anaconda
> #
> # Note that you do not have to rerun grub after making changes to this file
> # NOTICE:  You have a /boot partition.  This means that
> #          all kernel and initrd paths are relative to /boot/, eg.
> #          root (hd0,0)
> #          kernel /vmlinuz-version ro root=/dev/VolGroup00/LogVol00
> #          initrd /initrd-version.img
> #boot=/dev/md0
> default=0
> timeout=5
> splashimage=(hd0,0)/grub/splash.xpm.gz
> hiddenmenu
> title CentOS (2.6.18-194.11.1.el5PAE)
>        root (hd0,0)
>        kernel /vmlinuz-2.6.18-194.11.1.el5PAE ro root=/dev/VolGroup00/LogVol00 rhgb quiet crashkernel=128M at 16M
>        initrd /initrd-2.6.18-194.11.1.el5PAE.img
> title CentOS (2.6.18-194.11.1.el5)
>        root (hd0,0)
>        kernel /vmlinuz-2.6.18-194.11.1.el5 ro root=/dev/VolGroup00/LogVol00 rhgb quiet crashkernel=128M at 16M
>        initrd /initrd-2.6.18-194.11.1.el5.img

I would add a dummy entry to the end of grub.conf, something 
like this:

title Booting from "wherever I think GRUB and grub.conf is"
         root (hd0,0)
         kernel /vmlinuz-2.6.18-194.11.1.el5PAE ro root=/dev/VolGroup00/LogVol00 rhgb quiet crashkernel=128M at 16M
         initrd /initrd-2.6.18-194.11.1.el5PAE.img

Hit the down arrow at boot time, and if you don't see that 
entry above, then grub is using a different /boot/grub/grub.conf file.

I don't use RAID so cannot comment specifically on that. If 
you re-install GRUB to a seperate boot partition, when 
there are any kernel updates, yum will not know where to 
look to find and edit the grub.conf file. This means you 
have total control over which kernel gets booted, even after 
a kernel upgrade.

HTH

Keith Roberts

> ---- Fred Smith -- fredex at fcshome.stoneham.ma.us -----------------------------
>                       I can do all things through Christ
>                              who strengthens me.
> ------------------------------ Philippians 4:13 -------------------------------

So can I !!!