From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [PATCH RFC 0/9] [SCSI] Enhanced sense and Unit Attention handling Date: Thu, 24 Jan 2013 15:51:39 +0100 Message-ID: <51014A7B.2060806@suse.de> References: <1358526434-1173-1-git-send-email-emilne@redhat.com> <51011D2E.305@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from cantor2.suse.de ([195.135.220.15]:45045 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753937Ab3AXOvk (ORCPT ); Thu, 24 Jan 2013 09:51:40 -0500 In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Bart Van Assche Cc: "Ewan D. Milne" , linux-scsi@vger.kernel.org On 01/24/2013 03:38 PM, Bart Van Assche wrote: > On Thu, Jan 24, 2013 at 4:38 AM, Hannes Reinecke wrote= : >> As for AEN, does iSCSI _do_ AEN? I thought it got removed ... >> >> If it does, though, it should schedule an event on its own whenever = an AER >> is received. The same goes for LLDDs with vendor-specific AENs; thin= king of >> megaraid_sas here ... > > Let me ask this another way. SAN users expect that the LUN list at th= e > initiator side gets updated automatically after a SAN configuration > change. How should a SAN system communicate to a SCSI initiator that > the LUN list has been changed ? Some FC SAN systems send a LIP after = a > configuration change to force the initiator to rescan LUNs. And thereby disrupting traffic on _ALL_ LUNs on the loop. Really cool idea. I know; the one vendor which does _not_ talk to us. > But how to inform the initiator about a LUN change for other SCSI pro= tocols ? > I'm not sure that it is even possible to report such a change via=20 sense > data in case a SAN user first removes all LUNs and after that change > adds one or more LUNs. > The official way is indeed via UAs; most storage arrays (Hello,=20 NetApp!) provide a default LUN0 which is always visible. Up to the point that some even refuse to add 'normal' disk LUNs to=20 LUN0. Or have the ominous 'Well-known Address' LUN to handle these=20 kind of issues. Obviously, one needs to send commands to it to even _get_ an UA back. But yeah, normally it's possible. Cheers, Hannes --=20 Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=FCrnberg GF: J. Hawn, J. Guild, F. Imend=F6rffer, HRB 16746 (AG N=FCrnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html