diskid documentation

[Kurt Lidl]

> On Mon, Jun 2, 2014 at 9:26 AM, Allan Jude <allanjude at freebsd.org> wrote:
>> It also tends to sometimes hide the gpt label provider on me (not sure
>> in which cases it does this, but it is annoying)
>
> This happens when something (e.g. zfs) happens to open the diskid
> provider instead of the gpt label.  For me this ended up being a bit
> more than annoying; my swap was mounted in /etc/fstab via a gpt label
> so I silently lost my swap when I did an upgrade.

I have seen this too, starting from a fresh install.

The install process for stable/10 writes a /dev/gpt style label
into /etc/fstab for the swap space, and that never gets used,
because the /dev/diskid/xxxx stuff appears to take precedence.

I put the following into /boot/loader.conf to make the system more
sane:

kern.geom.label.disk_ident.enable=0

-Kurt