Mounting OpenBSD partitions

Wojciech A. Koszek wkoszek at
Wed Dec 6 07:39:34 PST 2006

On Wed, Dec 06, 2006 at 05:13:43PM +0200, Clayton Milos wrote:
> ----- Original Message ----- 
> From: "Alex Burke" <alexjeffburke at>
> To: "FreeBSD STABLE" <freebsd-stable at>
> Sent: Wednesday, December 06, 2006 3:18 PM
> Subject: Re: Mounting OpenBSD partitions
> >Hi,
> >
> >What you need is a GEOM module called nbsd. Here is the link:
> >
> >
> >This module is analgous to the default component (geom_bsd I believe
> >it is called) that understands FreeBSD disklabels, but instead it
> >understands NetBSD, OpenBSD and DragonFlyBSD disklabels.
> >
> >Once compiled and kldload'ed into the kernel, that module will allow
> >you to mount your partitions from the OpenBSD disk. However, note that
> >when I used it, there was some bug that did not allow you to get rid
> >of the module (cannot rememeber whether it panicked, hung or just
> >refused to unload), and so I simply rebooted once I had pulled the
> >data off the drive I needed to.
> >
> >Incidentally, it seems a great shame that FreeBSD does not deliver
> >this support in the base system, it would seem like a VERY useful
> >thing to be able to do for users and developers who use a couple of
> >the different BSD systems.
> >
> >Thanks and hope this helps, Alex J Burke.
> Alex
> You have a very valid point here.
> FreeBSD's support for other FS' is horiffic. Very little else is supported 
> which I find very sad.
> There is not even support for Solaris UFS. Something that would be really 
> nice would be support for XFS.

Actually, I've worked on Solaris labels support in the past. It meant
decoding their structures which is done:

Then, I hacked geom_sunlabel in order to accept minor changes between
way of handling SPARC/x86 differences (number of labels). Result of this
experiment was a set of readable slices and labels.

I don't remember exact differences between Solaris/FreeBSD UFS, but I
remember I was able to mess Solaris UFS with fsck(8) from FreeBSD, and
after "correcting" file system [1], I was able to read files from Solaris

[1] Solaris fsck(8) wasn't able to handle such serious brokeness, even
after specifying alternative, backup superblock.

Wojciech A. Koszek
wkoszek at

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