From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: generating a Linux WWN? Date: Wed, 03 Oct 2007 12:16:35 -0400 Message-ID: <4703C063.7050808@garzik.org> References: <50432.44268.qm@web31802.mail.mud.yahoo.com> <47032C67.8080109@garzik.org> <4703AE63.3010109@torque.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:56844 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753559AbXJCQQl (ORCPT ); Wed, 3 Oct 2007 12:16:41 -0400 In-Reply-To: <4703AE63.3010109@torque.net> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: dougg@torque.net Cc: ltuikov@yahoo.com, Michael Reed , James.Smart@Emulex.Com, linux-scsi Douglas Gilbert wrote: > Jeff Garzik wrote: >> Luben Tuikov wrote: >>> --- Jeff Garzik wrote: >>>> The admin will have the option to auto-generate a WWN, should they so >>>> desire. >>> What does that mean? "auto-generate"? By whom? >> The admin tells the kernel module to auto-generate a WWN, and the kernel >> module happily obliges. >> >> The generation algorithm is whatever makes people happy. I would >> probably pick a fixed prefix like 0x6C 0x69 0x63 ("lin"), something that >> doesn't conflict with IEEE org ids for a long time to come. Then, >> get_random_bytes() or hash some useful machine characteristics for the >> rest of the bytes. >> >> >>> What if they don't "auto-generate" (whatever that means)? >> Well, you either have a WWN or you don't :) > > Jeff, > It is not quite black and white. As I tried to point > out, when a SAS HBA is run in target mode, there is > a good chance there aren't _enough_ unique SAS addresses > allocated by the manufacturer. > > There should be naa-5 addresses for the ports, it is > the target device address and 0 or more lu addresses that > may need to be generated. Oh quite agreed ... I was definitely talking about the initiator. The thread has come full circle again :) I would definitely like to figure out a standard way to generate new SAS addresses. Jeff