Subject: Re: System unique identifier.....
To: Wilko Bulte <wilko@yedi.iaf.nl>
From: Matthew Jacob <mjacob@feral.com>
List: tech-kern
Date: 06/26/1999 08:38:09
On Sat, 26 Jun 1999, Wilko Bulte wrote:

> As Matthew Jacob wrote ...
> > 
> > Yes, you want the WWN to stay constant. That doesn't mean it should
> > necessarily be the same physical box. Nor does it mean it should be a
> > system that comes with a WWN assigned to by the manufacturer.
> 
> Manufacturers have to register and 'get' a unique range they can assign
> to their products. How do you guarantee that your homegrown WWN is
> really unique?

Witha a value in the top 4 bits that's not one of the currently defined
authoritative values.

> 
> > I think I'm confusing myself and people. I have a WWN. By definition it
> > should be unique value. All I'm asking for is a kernel function to help me
> > generate such a thing (despite what Eduardo says).
> > 
> > 
> > On Fri, 25 Jun 1999, Wilko Bulte wrote:
> > 
> > > As Matthew Jacob wrote ...
> > > > > 
> > > > > FYI: The Compaq HSG80 Fibrechannel RAID controllers have their 
> > > > > WWN in NVRAM. One is supposed to get the WWN from a label on the *cabinet*
> > > > > into the HSG controller. This allows for easy hardware swap in case of
> > > > > hardware grief.
> > > > 
> > > > Yes, if you want the WWN to stay constant.
> > > 
> > > Well, you do. Especially when you are using things like zoning (like
> > > that Brocade switches can do) or when the host directly ties things to
> > > the wwn it talks to. E.g. for connection to Sun we use Jaycor adapters
> > > that allow things like "target=foo lun=bar www="<64bitnumber>" in the
> > > Solaris /kernel/drv/sd.conf file
> > 
> > And to boot a Sun over fibre channel, you use the WWN.
> 
> Well, we currently don't support that, but indeed that is what you would
> do. Tru64 Unix does something similar.


You can boot off of fibre channel now- but not using a WWN.

I want to see devfs fixed and using WWWs and/or device VPD.

-matt