After changing the configuration of kdump by editing the /etc/kdump.conf file, restarting the kdump service fails with the following error:

# /etc/init.d/kdump restart
Stopping kdump:             [ OK ]
Detected change(s) the following file(s):

/etc/kdump.conf
Rebuilding /boot/initrd-2.6.32-431.20.3.el6.x86_64kdump.img
No module linuxshield found for kernel 2.6.32-431.20.3.el6.x86_64, aborting.
Failed to run mkdumprd
Starting kdump:              [FAILED]

This did not happen on Red Hat Enterprise Linux 5 or Cent OS 5.