Re: generating a Linux WWN?

Michael Reed
2007-09-27T15:07:19Z

Matthew Wilcox wrote:
> On Thu, Sep 27, 2007 at 09:16:13AM -0500, Patrick_Boyd@Dell.com wrote:
>> > Unfortunately, it looks like IEEE doesn't have any OID's registered for
>> > Linux or other reserved areas
>> > (http://standards.ieee.org/regauth/oui/oui.txt). However, it does look
>> > like they go in order... so maybe if you used an OID of 0xFFFFFF you
>> > could at least guarantee that you didn't conflict with any company's SAS
>> > WWNs.
>
> It's something that happens frequently enough that we should come up
> with a proper way of handling this. I heard a story of someone at HP
> taking an old computer, reading the MAC address from the motherboard,
> then snapping the board in half. I suppose if you're going to use a MAC
> address from a 10Mbit ethernet card for a SAS WWN, there's no chance of
> conflict, but still ... 3com might choose to do the same thing, and then
> we're in trouble.

Record the WWN of your SAS / FC port so that if/when it goes missing you
can put it back? Have spares on site?

>
> I don't have a good solution for WWN assignment. Even if we get a
> 24-bit OID assignment for 'software use' or something, how do we control
> the use withi the SAN to be sure we get no overlapping WWNs?

Your point here is that overriding a WWN assignment is asking for trouble.

Mike