Where has my /dev/label gone?

[Warren Block]

On Wed, 19 Feb 2014, lucian at lastdot.org wrote:

> I have GEOM_LABEL loaded, but I noticed something strange.
> If I boot in single user, I can create and see the labels under /dev/label, 
> however if I remount the / filesystem RW then /dev/label disappears.
> BUT, if I just replace my / partition in fstab with the seemingly missing 
> label (eg /dev/label/rootfs) then the system boots up fine and /dev/label is 
> again available to `ls`. Strange stuff, it should be covered in the 
> handbook...
> Problem solved, I guess.

GEOM hides devices that are mounted.  Most of them, or some of the time, 
or maybe only certain types, the rules are not clear.