root@rocha:~# mount -t ufs -o ufstype=ufs2,ro /dev/hda4 /mnt/openbsd
mount: wrong fs type, bad option, bad superblock on /dev/hda4,
       missing codepage or other error
       In some cases useful info is found in syslog - try
       dmesg | tail  or so

####dmesg tail

ufs was compiled with read-only support, can't be mounted as read-write
ufs_read_super: bad magic number

###fdisk -l

/dev/hda4   *        1934        2865     7486290   a6  OpenBSD