[PLUG] CentOS kernel update puzzle regard grub.conf default kernel

[Galen Seitz]

Joe Pruett wrote:
>> I have two CentOS 5 machines that I just updated to 5.4.  On both
>> machines the new kernel was inserted into the top of the list in
>> grub.conf.  However, on one machine the default line in grub.conf was
>> changed such that the old kernel would boot by default.  On the other,
>> default was left at 0 so the new kernel would boot.  This is not the
>> first time I've seen this behavior.  What controls whether the default
>> gets changed on a kernel update?  I can't think of anything I would
>> have done that would cause these two machines to behave differently.
> 
> make sure that /etc/sysconfig/kernel has the correct type of kernel 
> configured.  if you are running smp, but the config file doesn't say that, 
> then the grub file won't be updated.

Thanks.  /etc/sysconfig/kernel does not exist on the machine that 
defaults to the old kernel.  I don't recall manually creating 
/etc/sysconfig/kernel on the other machine.  Does one of the GUI admin 
tools create this file?  Obviously I can just copy the file, but I'm 
curious how I got into this situation.

-- 
Galen Seitz
galens at seitzassoc.com