Is it possible to mount OpenBSD FFS partitions in FreeBSD?

Nikola Lečić nikola.lecic at
Mon Dec 31 03:37:02 PST 2007

On Mon, 31 Dec 2007 12:16:50 +0100
"Seth Brundle" <cdanza335 at> wrote:
> 2007/12/31, Nikola Lečić <nikola.lecic at>:
> >
> > On Mon, 31 Dec 2007 11:58:17 +0100
> > "Seth Brundle" <cdanza335 at> wrote:
> >
> > [...]
> > > # mount /dev/ad8s1a /mnt/
> > > mount: /dev/ad8s1a : No such file or directory
> > >
> > > (I thought that the first -- and only -- partition on OpenBSD
> > > would show up as 'slice 1' on FreeBSD.)
> >
> > (The disk area occupied by OpenBSD is a slice, whilst BSD-style
> > chunk(s) within are partitions.)
> >
> > Is it possible to mount it just with 'mount /dev/ad8s1 /mnt'?
> Thanks for your fast reply;
> # mount /dev/ad8s1 /mnt
> mount: /dev/ad8s1 : No such file or directory
> Also tried this before, doesn't work. The main problem for me is that
> I don't know the way the OpenBSD disc appears to FreeBSD,
> layout-wise. A ``disklabel ad8'' to have a peek also doesn't work:

Ah sorry, I misunderstood you; the ad8 is dedicated to OpenBSD in its
entirety? In that case I'm pretty sure that, in standard cases, it
should be possible to mounted it as /dev/ad8. (Yes, you wrote that it's
seen as wd2a from OpenBSD.)

(Btw, what does 'ls /dev/ad*' show?)
> # disklabel ad8
> disklabel: /dev/ad8: no valid label found

This is expected, BSD labels are not compatible among BSDs:

     The various BSDs all use slightly different versions of BSD labels
     and are not generally compatible.

(from bsdlabel(8) manpage).

That's why you can't (by default) see BSD labels created by another
BSD. However, I know that first partition of a NetBSD slice/disk can be
mounted from FreeBSD _without_ partition-letter addition (e.g. ad8 will
represent what you would expect to be ad8a -- it the disk is
"dedicated" -- and ad8s1 will represent what you would expect to be
ad8s1a -- if the disk is sliced), but maybe OpenBSD does something

Nikola Lečić :: Никола Лечић

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