Re: generating a Linux WWN?

Michael Reed
2007-09-27T15:12:44Z

Michael Reed wrote:
>
> 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?

Our vendor recommends fixing the board, not applying a band-aid. A random
WWN will potentially not work as the board firmware does some level of
sanity checking. YMMV.

Mike

>
>> 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
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