Geom, MBR, labels, and usb sticks

[Warren Block]

On Thu, 19 Jul 2012, Dave Hayes wrote:

> On 07/19/12 20:50, Warren Block wrote:
>> On Thu, 19 Jul 2012, Dave Hayes wrote:
>>> and still the labels do not show up.
>> 
>> They won't show in gpart because they are filesystem labels.  They will
>> show in 'tunefs -p' or 'file -s'.
>
> Thank you for that. I was able to verify that tunefs -p works.
>
>>> I really do want to be able to mount /dev/ufs/foo as the root device,
>>> but as I understand things if gpart doesn't show the label then the
>>> glabel subsystem won't set up the proper device file.
>>> 
>>> What gives here? Am I missing something important?
>> 
>> There is more than one type of label.  glabel(8) has a list that
>> includes the device directory where the label appears.
>
> Right. However if the label is not showing up in /dev/ufs/<label>
> what are my debugging options?

The label won't appear until the device has been retasted.  That can be 
forced with 'true > /dev/ada0p2' or by rebooting.  Labels can also be 
hidden when a device is in use (mounted).

If the label still doesn't show, the only other thing that comes to mind 
is a custom kernel that is missing the needed GEOM modules.