raid not auto detecting

[Jason Wong]

After setting up raid, the box is unable to autodetect the raid 1 array.
doing a cat /proc/mdstat shows that the array is not running however
when I type raidstart /dev/md0, then do a cat /proc/mdstat, everything is
fine
I'm running a stock rh 6.0 install.  Where can i look to autodetect and
start my
raid arrays?  TIA for any help.