I think the link that Bozon gave you is misleading. You need to use the "zpool attach" command to attach a formatted drive to the already existing zpool called "rpool", if you try to use the "zpool create" command mirror a drive that already has OpenSolaris on it, you will get an error message. Or at least that's what I got when I tried it. The dark star "zpool attach" method is what works best with OpenSolaris 2008.05 and probably 2008.11 as well.
I tried it and it worked. -- This message posted from opensolaris.org
