backup drive bootabel

[Noah]

FreeBSD 4.8-stable


I have about three different sources for making a drive bootable.  well I have
a  machine with two drives and the second drive is an exact backup of the
first.  but I need to make the 2nd drive bootable as well since this drive
will be plopped in if the first drive goes bad.  any recommendations on how to
do this?

Please send me to a good web tutorial if need be.

- Noah