From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Reed Subject: Re: generating a Linux WWN? Date: Thu, 27 Sep 2007 10:07:15 -0500 Message-ID: <46FBC723.2070607@sgi.com> References: <46FB8024.8040807@garzik.org> <46FBB86B.8000206@emulex.com> <20070927144649.GV3899@parisc-linux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from netops-testserver-4-out.sgi.com ([192.48.171.29]:35007 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754530AbXI0PHT (ORCPT ); Thu, 27 Sep 2007 11:07:19 -0400 In-Reply-To: <20070927144649.GV3899@parisc-linux.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Matthew Wilcox Cc: Patrick_Boyd@Dell.com, James.Smart@Emulex.Com, jeff@garzik.org, linux-scsi@vger.kernel.org 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