Name/label/id metadata: how do I make it go away

[Warren Block]

On Mon, 21 Sep 2015, Chris Stankevitz wrote:

> Warren/Freddie,
>
> Thank you for your replies.
>
> On 9/21/15 8:41 PM, Warren Block wrote:
>>> - gpt id
>> 
>> A system-assigned ID in the GPT metadata.  Requires GPT partitioning.

ZFS on bare devices uses an EFI label that is similar or related to GPT. 
Those might be detected and displayed even without GPT, but I'm not 
sure.

>>> I have a zfs pool of "entire disks".  "zpool status" shows some disks
>>> with their daX name (which I prefer) and some with a hideously ugly
>>> name such as DISK-%20%20%20%20%20-WD-WMC4NOH1ASDF
>> 
>> Disable those labels with kern.geom.label.gptid.enable="0" in
>> /boot/loader.conf.
>
> Combining your two statements quoted above, I believe I can conclude that my 
> ZFS "whole disk" drives must have some remnants of GPT left over from their 
> previous lives (namely the system-assigned ID in the GPT metadata).
>
> Surprisingly, these apparently GPT-supplied labels appear to "go away" when I 
> issue a "glabel stop".  I would not expect this given that Warren explained 
> that glabels (whose metadata are stored at the end of the device and 
> completely outside the virtual device) are not the same as GPT labels (whose 
> metadata are stored within the device on the GPT metadata).

"glabel" is both a command that creates manual labels and a GEOM class 
that creates the entries in /dev when device labels of all types are 
found.  Stopping the label class stops the display of all labels. 
glabel(8) is worth the read.