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

Kai Schaetzl maillists at conactive.com
Wed May 7 22:19:50 UTC 2008


Lanny Marcus wrote on Wed, 07 May 2008 15:10:58 -0500:

> Kai: I am not using Windows Boot Manager. Grub comes up, as on the 2
> boxes, where things are working properly.

Just to be sure, it's really grub? You get a somewhat blueish screen that 
says "booting centos in x seconds, press any key to see options" or so? I 
think there's also a CentOS symbol on it, but am not sure. We have to be 
absolutely sure about that.
And if you select Windows from that boot screen, does that boot right into 
Windows or do you get another boot menu that lists only Windows?

> Questions: (a) Can I copy /boot/grub/grub.conf on my box and replace
> that file on my wife's box, with my version? Would that work OK? Worth a
> try?

No, this wouldn't help, because the grub.conf that *we know of* is fine. 
It's just not getting used, because you are booting from another one. 
AFAIK, grub cannot embed a boot menu in the MBR (Master Boot Record), so 
that information must be coming from somewhere else.
You have *two* grub.conf's (and two /boot partitions) on the machine 
AFAIS. You would have to *merge* the two: you need the options for booting 
Windows from the first one and all the other options from the second one.
AFAIK, the MBR on your disk does not boot from hd(0,2), but from another 
partition. You have to find out which one that is and change the grub.conf 
on that partition accordingly. The caveat of this is that you would have 
to do this each time the kernel changes or you would need to change a bit 
more, so that this becomes the new boot partition.
Another option would be to grub-install again and overwrite the current 
information in the MBR, so that it then boots from hd(0,2).
I'm not confident enough about both options to talk you thru.
Maybe I'm missing other possibilities why that happens, but the basic 
problem is that your machine does not boot from that hd(0,2), but with 
information from elsewhere.

> There was confusion on my part, when I installed Windows XP on my wife's
> box. Hers was the first one I installed Win XP on, which I'd never
> installed before and it ended up getting installed more than once.

Did you install it after CentOS or before it?
You will need to make a list of all partitions. Not sure what the best way 
to do this would be. Probably fdisk. Run fdisk, then type "p" (for 
printing the partition table), then leave it with "q". Be careful, as 
printing the table is only the least dangerous action in fdisk!


Kai

-- 
Kai Schätzl, Berlin, Germany
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