# mount -t tmpfs none /mnt
# zpool create -o altroot=/mnt -m /bootpool -f bootpool mirror \
mfid0p2 mfid1p2 mfid2p2 mfid3p2 mfid4p2 mfid5p2 mfid6p2 \
mfid7p2 mfid8p2 mfid9p2 mfid10p2 mfid11p2
# mkdir -p /mnt/bootpool/boot
# zfs unmount bootpool
# umount /mnt