[Centos] Kernel Panic on New Kernel Package

[ryan@xxxxxxxxxxxxxx (Ryan Lane)]

Josh,

Sounds like a strange problem indeed.  Off the top of my head, try 
running mkinitrd manually for the new kernel (in verbose mode), to make 
sure that it is preloading all of the modules necessary to boot your / 
filesystem.  Specifically make sure it is loading the raid1 module, and 
the ext3 module (assuming / is formatted ext3).  Also, if your drives 
are other than regular IDE (scsi or sata), make sure the appropriate 
scsi or sata modules are getting loaded.  To run mkinitrd in verbose 
mode, just pass it the -v flag.  So in this case your command would look 
like this:

mkinitrd -f -v /boot/initrd-2.4.21-20.0.1.ELsmp.img 2.4.21-20.0.1.ELsmp

Try that first to make sure the modules are getting loaded.

-Ryan