How to label a GELI device

[J. Porter Clark]

On Tue, Jan 25, 2011 at 10:45:52AM +0200, Nikos Vassiliadis wrote:
> J. Porter Clark wrote:
> > I have an encrypted partition, /dev/da0s1d.  I can use geli
> > attach da0s1d and obtain a device /dev/da0s1d.eli, which is a
> > UFS filesystem.  All that works just fine.
> > 
> > I'd like to label /dev/da0s1d so that I don't have to refer to
> > the exact drive number, etc., which might change if I reboot
> > with a USB stick in the system or whatever.  But glabel puts the
> > label in the last sector, which is where GELI stores metadata.
> 
> You don't have to worry about this. geli uses the last sector for
> its metadata and creates a device with one sector less to its clients.
> The original device is 2048 sectors, the device geli provides is 2047
> sectors:
> > moby# diskinfo /dev/md0 /dev/md0.eli
> > /dev/md0        512     1048576 2048    0       0
> > /dev/md0.eli    512     1048064 2047    0       0
> 
> There is no way for the "internal" GEOM to mess with the "external's"
> metadata.

That's fine, but I want to label the "external" /dev/md0, not
the "internal" /dev/md0.eli.

What I eventually want to do is to "geli attach" the device
using a name that doesn't depend on drive numbering.

-- 
J. Porter Clark      <jpc at porterclark.com>