No space in lost+found directory (SORRY. NO SPACE IN lost+found DIRECTORY)

Type as root:

# mount -f /dev/ad0s1a /tmp_mnt
# rm -rfv /tmp_mnt/lost+found/
# mkdir /tmp_mnt/lost+found
# umount /tmp_mnt
# fsck -y /dev/ad0s1a
# reboot