[CentOS] Re: CentOS 4.5 system doesn't boot after installing latest updates

[James A. Peltier]

Phil Schaffner wrote:

<snip>
> I have seen this behavior before when the BIOS device order does not
> match what is seen by the running system.  Seems that in such cases,
> running GRUB from the boot media also sees different device/controller
> ordering than the running system and can lead to GRUB being confused
> about where to find the stage1 part of the GRUB code.  Either changing
> the device order in the BIOS settings (if that is an option) or changing
> the order controllers are found in /etc/modprobe.conf seems to help.  In
> any case, check /boot/grub/device.map and assure that it matches what
> GRUB sees at boot time.  Can check this with the GRUB shell "find"
> command.
>   
</snip>


It's interesting that you mention this as it jogged my memory to a case 
that happened to me when I tried Fedora 8 recently.  Since my system is 
quite a hodgepodge of drives when I booted F8, it detected the drives in 
an odd order.  The OS installed fine but wouldn't boot afterwards.  Upon 
booting into rescue mode I was able to make adjustments to the device 
map to get it to alter the way the system booted to match the way F8 saw 
it at install.  It was very hit and miss and I just attributed it to 
being a beta.  Anyways, my suggestion is to check all the drives in your 
system for said files as mentioned.  If they are there, but not where 
grub is looking for you may have to make changes.