From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: Persistent reservation behaviour/compliance with redundant controllers Date: Tue, 07 Jan 2014 07:06:19 +0800 Message-ID: <1389049579.2811.12.camel@dabdike> References: <52CB2C44.7040503@suse.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: 7bit Return-path: Received: from bedivere.hansenpartnership.com ([66.63.167.143]:54330 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755928AbaAFXGX (ORCPT ); Mon, 6 Jan 2014 18:06:23 -0500 In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Matthias Eble Cc: Lee Duncan , linux-scsi@vger.kernel.org On Mon, 2014-01-06 at 23:53 +0100, Matthias Eble wrote: > 2014/1/6 Lee Duncan : > > On 12/25/2013 03:00 PM, Matthias Eble wrote: > >> Here's the dmmp map > >> 360002ac0000000000000000a00006e6b dm-6 3PARdata,VV > >> size=2.0T features='0' hwhandler='0' wp=rw > >> `-+- policy='round-robin 0' prio=1 status=active > >> |- 3:0:1:4 sdg 8:96 active ready running > >> |- 3:0:3:4 sdl 8:176 active ready running > >> |- 5:0:3:4 sdbg 67:160 active ready running > >> `- 5:0:1:4 sdce 69:32 active ready running > >> > >> There can only be two registrations at a time: (sdg XOR sdl) and (sdbg XOR sdce) > >> Now my question is: Does this comply to the standard? > >> > > > > I _believe_ the problem is that you are re-registering the same > > I_T_Nexus through /dev/sdl, your second attempt at registration, as you > > did when you used /dev/sdg, your original registration. > > > Can sdg and sdl be the same I_T_Nexus at a time? > Right now, they are handled like that. > In my understanding, every scsi disk device represents an I_T_Nexus. No, every SCSI disk is an I_T_L nexus. There's no actual device object in Linux for an I_T nexus. James