Note: CentOS will kernel panic in many cases where another distro will drop to
the initramfs or rescue shell. This includes when it can't find the root
device.

This is an example of a panic from the UUID for the root filesystem being
wrong in fstab and /boot/grub/menu.lst:

Kernel panic - not syncing: Attempted to kill init!
PID: 1, comm: init Not tainted 2.6.32-431.1.2.0.1.el6.x86_64 #1
Call Trace:
 [<ffffffff81527213>] ? panic+0xa7/0x16f
 [<ffffffff81077622>] ? do_exit+0x862/0x870
 [<ffffffff8118a875>] ? fput+0x25/0x30
 [<ffffffff81077688>] ? do_group_exit+0x58/0xd0
 [<ffffffff81077717>] ? sys_exit_group+0x17/0x20
 [<ffffffff8100b072>] ? system_call_fastpath+0x16/0x1b