[CentOS] centos4.2:raid1:grub

Hi!
Whew, I have googled around a lot w/this but can't quite seem to come up
w/the right answer.

This system works beautifully w/nothing wrong w/it. But my goal is to be
able to test the raid system by just unplugging hda to mimic a faulty
drive and have it just carry on and boot from hdc.

md0 = hda1/hdc1  /boot (primary boot partitions on both drives)
md1 = hda2/hdc2  /

is it possible to just edit /boot/grub.conf???  I am really not sure of
this 

Thx in advance.

John Rose