Another test that might be useful is booting from a kfreebsd-9 rescue image and trying to import your pool from command-line (zpool import -o altroot=/target base).
If that fails it'll probably give more useful diagnostics. -- Robert Millan -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org