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

Tue Sep 25 10:38:35 UTC 2007
Alfred von Campe <alfred at von-campe.com>

> Out of interest, is this something that is always required when  
> upgrading Grub?
> i.e. should one always manually run "grub-install" /dev/XXX" after  
> doing so?

No, it shouldn't.  But in my case, I didn't "upgrade grub".  I simply  
did a "yum update" which installed, among other things, a new kernel,  
so a reboot was needed.  And when I rebooted, grub wouldn't start.   
So I booted into rescue mode from the CentOS CD #1, and did a "rpm -e  
grub kernel" followed by "yum install grub kernel".  This did not fix  
the problem.  I had to boot into rescue mode again and do a "grub- 
install /dev/sda".  The big question remains, what happened on my  
system that corrupted the MBR.  I could have been anything at all  
since the last time I rebooted (about a month ago) and not  
necessarily the "yum update".