Some minor updates. I suggest we commit this now to get rid of the old instructions that create a non-booting gmirror. If/when the situation with GPT and gmirror becomes simpler, we can replace or rewrite this section again. http://www.wonkity.com/~wblock/gmirror/geom-mirror.html http://www.wonkity.com/~wblock/gmirror/geom.diff