From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: [dm-devel] mechanism for multipath to pass information to hardware handler Date: Fri, 26 Jun 2009 14:55:54 -0500 Message-ID: <1246046154.3925.80.camel@mulgrave.site> References: <1245863681.8709.135.camel@eddie-laptop> <1246043447.3925.64.camel@mulgrave.site> <1246045509.14164.33.camel@chandra-ubuntu> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from bedivere.hansenpartnership.com ([66.63.167.143]:55591 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756069AbZFZTzz (ORCPT ); Fri, 26 Jun 2009 15:55:55 -0400 In-Reply-To: <1246045509.14164.33.camel@chandra-ubuntu> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: sekharan@linux.vnet.ibm.com Cc: device-mapper development , SCSI development list , "Rafael J. Wysocki" , Mike Christie , Edward Goggin , "Benoit, Arthur" , asson_ronald , berthiaume_wayne On Fri, 2009-06-26 at 12:45 -0700, Chandra Seetharaman wrote: > Yes, Mike Christie and I were aware of this and it was one of the issue > we were trying to resolve before we pushed scsi_dh interface upstream. > (It is little complicated as we need the parameters to be set per > vendor-product tuple). > > The original code I ported to scsi_dh interface was from Ed Goggin(who > was working for EMC then). IIRC, he was also aware of this issue. > > When we pushed scsi_dh interface, we did get few of the EMC folks (on > Cc) to review/test the code and they did, and this issue was not seen as > a problem. > > We wanted to get back to that issue sometime later, got busy with other > things, and it disappeared from my list of things-to-do as the > regression was not seen as an issue (till now :)... I will get back to > it. One way around this might simply be to make the device_handlers create a sysfs interface for additional parameters. Then the multipath command can feed them (or in a pinch, users relying on the features can pass them in manually). Right at the moment having no possible work around does appear to be an issue. James