root@ubuntu:~/test# dmesg|grep bsd
[    4.255161]  sda1: <bsd:bad subpartition - ignored
[  207.370765] mount -t ufs -o ufstype=sun|sunx86|44bsd|ufs2|5xbsd|old|hp|nextstep|nextstep-cd|openstep ...
[  211.545992] mount -t ufs -o ufstype=sun|sunx86|44bsd|ufs2|5xbsd|old|hp|nextstep|nextstep-cd|openstep ...
[  259.818467] mount -t ufs -o ufstype=sun|sunx86|44bsd|ufs2|5xbsd|old|hp|nextstep|nextstep-cd|openstep ...
[  279.546550] mount -t ufs -o ufstype=sun|sunx86|44bsd|ufs2|5xbsd|old|hp|nextstep|nextstep-cd|openstep ...
[  288.314483] mount -t ufs -o ufstype=sun|sunx86|44bsd|ufs2|5xbsd|old|hp|nextstep|nextstep-cd|openstep ...

root@ubuntu:~/test# mount -r -t ufs -o ufstype=ufs2 /dev/sda /root/test/
mount: wrong fs type, bad option, bad superblock on /dev/sda,
       missing codepage or helper program, or other error
       In some cases useful info is found in syslog - try
       dmesg | tail  or so

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *          63   488397167   244198552+  a5  FreeBSD