From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ewan Milne Subject: Re: [PATCH v3 0/6] [SCSI] Enhanced sense and Unit Attention handling Date: Mon, 22 Jul 2013 17:13:22 -0400 Message-ID: <1374527602.4139.27.camel@localhost.localdomain> References: <1371663761-22481-1-git-send-email-emilne@redhat.com> <1374507094.2335.21.camel@dabdike> Reply-To: emilne@redhat.com Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from mx1.redhat.com ([209.132.183.28]:8513 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757004Ab3GVVN0 (ORCPT ); Mon, 22 Jul 2013 17:13:26 -0400 In-Reply-To: <1374507094.2335.21.camel@dabdike> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: James Bottomley Cc: "linux-scsi@vger.kernel.org" , "rwheeler@redhat.com" , Kirill Korotaev On Mon, 2013-07-22 at 15:31 +0000, James Bottomley wrote: > Ping on this, please. > > I have another possible consumer of this infrastructure, when it's > ready, which is the SCSI RAID drivers. We've been getting complaints > that there's no event we get from them when a RAID system goes from > online -> degraded which should be the sysadmin's cue to go in and > replace the disk (well, this isn't quite true, a lot come with > proprietary monitoring daemons which do this, but they're pretty unique > per controller). > > I was thinking we might resurrect the orphaned raid_class.c to do this > and give a universally displayable but rudimentary view of the topology > and health of the device and add an easy hook for RAID events. > > James > I'm testing a v4 version of these patches, which address your earlier comments. I'm still working on the code to suppress the duplicate REPORTED LUNS DATA HAS CHANGED unit attentions from multiple LUNs. As I mentioned in my earlier mail, doing this with the expected_cc_ua mechanism is imperfect, because SCSI-3 devices will stop reporting it when one of the LUNs on the target *receives* a REPORT LUNs command, and it is difficult to know when this happens. I'm trying out clearing the flag before the SCSI scan code issues a REPORT LUNs, that might be good enough. (It doesn't handle someone from sending this command through the sg driver, though.) Will post the v4 soon. -Ewan