[CentOS] "yum update" did not update kernel on one box

Lanny Marcus lannyma at gmail.com
Tue May 13 15:27:21 UTC 2008


On Mon, 2008-05-12 at 10:52 -0400, Ross S. W. Walker wrote:
> lannyma at gmail.com wrote:
> > 
> > On 5/8/08, Kai Schaetzl <maillists AT conactive DOT com> wrote:
> > <snip>
> > > hda3 and hda9 are your Linux LVM partitions, maybe they belong to one volume
> > > group, I don't know (your fstab would tell more, there's also a graphical
> > > frontend for LVM in your desktop).
> > >
> > > From your grub.conf we know that it thinks it's installed on (hd0,2), but
> > > hd0,2 is hda3 (if I understand that correctly) and that is LVM, and grub
> > > can't boot from LVM because grub boots the kernel and only that knows about
> > > LVM. So, you are probably booting from hda8, but it's not in your fstab as
> > > the  /boot partition.
> > >
> > > What does a "df" say? Does it list hda8 among the partitions? Probably not?
> > 
> > [root at compaq1300 ~]# df
> > Filesystem           1K-blocks      Used Available Use% Mounted on
> > /dev/mapper/VolGroup00-LogVol00
> >                       10696956   4597688   5547128  46% /
> > /dev/hda3               102486     22174     75020  23% /boot
> > tmpfs                   257260         0    257260   0% /dev/shm
> > [root at compaq1300 ~]#
> > 
> > > Mount it and have a look at that partition, does it contain the same stuff
> > > as your /boot partition? If not mounted, do:
> > > mkdir /mnt/hda8
> > > mount /dev/hda8 /mnt/hda8
> > > cat /mnt/hda8/boot/grub/grub.conf
> > > Does this look like the grub.conf that is the *real* one booting your system?
> > 
> > [root at compaq1300 ~]# mkdir /mnt/hda8
> > [root at compaq1300 ~]# mount /dev/hda8 /mnt/hda8
> > [root at compaq1300 ~]# cat /mnt/hda8/boot/grub/grub.conf
> > cat: /mnt/hda8/boot/grub/grub.conf: No such file or directory
> > [root at compaq1300 ~]#
> 
> The proper location of the grub.conf is:
> 
> /mnt/hda8/grub/grub.conf
> 
> 'boot' was the name of the mount point which isn't part of the 'boot' file system.
> 
<snip>
> 
> Kai, is right though, chances are grub from the MBR is looking into a
> different partition for it's config and shows one of the problems with
> grub. I think there is a version of grub that will keep it's configs
> in the remaining sectors (sectors 2-62) of the first track and boot
> the kernels directly from another partition, but that's non-standard.
> 
> You could use a single 'boot' partition for all your Linux distros
> though, but make it bigger, say 256MB (or 512MB if you have a lot
> of distros installed).

Ross: You suspect that I have more than one Linux distro installed, but
that is not true. There are 2 OS installed: (a) MS Windows XP Home
Edition (the installation of that did not go well on the box with this
problem) and (b) CentOS 5. After I wiped the HDs in the 3 boxes, last
Thanksgiving weekend, each of them got a /boot partition of
approximately 100 MB.  If you have any ideas that are non destructive,
please let me know what they are. If this problem was on my box or my
daughters box, worst case is I would "learn by destroying" and need to
wipe the HD and start over. However, this is on my wife's box and if I
screw it up, I have problems with her.  :-)   TIA, Lanny

> I would typically have /dev/hda1 setup as a 256MB 'boot' and reuse it
> for other distros, just make sure not to format it on install or you'll
> bork the first distro's kernels!
> 
> -Ross




More information about the CentOS mailing list