From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bart Van Assche Subject: Re: dm-multipath: Accept failed paths for multipath maps Date: Wed, 19 Feb 2014 09:11:55 +0100 Message-ID: <5304674B.4020001@acm.org> References: <1387353155-7271-1-git-send-email-hare@suse.de> <20131218140858.GC17730@redhat.com> <52B1B046.3040301@suse.de> <1387380498.7608.6.camel@ict-vth-stewarts01.ict.englab.netapp.com> <52B2AC96.8010909@acm.org> <20140219011401.GA17796@redhat.com> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20140219011401.GA17796@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Mike Snitzer Cc: device-mapper development , "Stewart, Sean" , Alasdair Kergon List-Id: dm-devel.ids On 02/19/14 02:14, Mike Snitzer wrote: > On Thu, Dec 19 2013 at 3:21am -0500, > Bart Van Assche wrote: > >> On 12/18/13 16:28, Stewart, Sean wrote: >>> The most severe case is with >>> InfiniBand, where the LLD may place a device offline, then every single >>> reload that is trying to add a good path in will fail. I will qualify >>> this by saying that I realize it is a problem that the device gets >>> placed offline in the first place, but this patch would allow it a >>> chance to continue on. The user still has to take manual steps to fix >>> the problem in this case, but it seems less disruptive to applications. >> >> Are you perhaps referring to the SRP initiator ? The above is correct >> for old versions of the SRP initiator (< Linux kernel 3.12) but no >> longer for upstream kernel versions >= 3.12. An effort is ongoing to >> backport the latest SRP initiator changes into RHEL and SLES. > > It has been a while. Where do things stand for the RHEL backport of > these SRP initiator changes? Are we talking RHEL6 and RHEL7? Who at > Red Hat is your contact for this work? > > Regardless of whether some version of Hannes's patch is applied to > upstream dm-mpath: I'd really like to see this offlining problem that > forced the need for this dm-mpath change addressed. Hello Mike, At https://github.com/bvanassche/ib_srp-backport a version of the SRP initiator driver can be found that works fine with at least RHEL 6.3, 6.4, 6.5 and SLES 11. I have not yet had a chance to test that driver against RHEL 7. The SRP initiator driver backport includes all changes that have been accepted upstream up to and including kernel 3.14-rc3. That means that both versions of the SRP initiator driver include the code that changes the SCSI device state from "offline" into "running" after reconnecting succeeded after a cable pull. The relevant RHEL bugzilla entries are as follows: * https://bugzilla.redhat.com/show_bug.cgi?id=1012926 * https://bugzilla.redhat.com/show_bug.cgi?id=1055654 Thanks, Bart.