glabel clarification

Polytropon freebsd at
Tue Oct 20 03:28:10 UTC 2009

On Mon, 19 Oct 2009 11:58:18 -0400, PJ <af.gourmet at> wrote:
> Actually, I have been trying to clone a disk and then install the disk
> in another machine or same clone in several machines. That's why I
> thought that once the clone is make it would boot on any machine. This
> in presuming that each clone is identical including the fstab file; I
> understood that this would allow immediate bootup regardless of what the
> disk may be ad4, ad1, ad12 or whatever.

I think that's a possible explaination. I'm guessing: If the
labels of both disks have the same names, and both disks are
present at booting time, and /etc/fstab contains those labels,
then maybe if both disks have identical labels, then instead
from the booting disk ad6, the ad12 disk labels are used for
file system mounting?

The easiest way REALLY is to extract one disk from the system
and use only one disk for booting tests. Let's say you've
already transfered data from ad6 (source) to ad12 (target)
successfully. Now unplug ad6 and let the system boot from
ad12. It should work. Then, put ad12's disk to ad6's controller.
So now the former ad12 is ad6. Because you're using labels,
it shouldn't matter. Try to boot. Should work as well.

This really is the easiest way to check.

> I can still clone the disk but then just have to
> find what disk is the clone.

Clones are identical. :-)

Seriously: There is a way to determine it definitely: Have a
look at the UFSID class labels. They should be unique, even
if glabel labels are identical.

Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...

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