From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx2.redhat.com (mx2.redhat.com [10.255.15.25]) by int-mx2.corp.redhat.com (8.13.1/8.13.1) with ESMTP id l1K6Bsui002758 for ; Tue, 20 Feb 2007 01:11:55 -0500 Received: from percy.comedia.it (percy.comedia.it [212.97.59.71]) by mx2.redhat.com (8.13.1/8.13.1) with ESMTP id l1K6BqU6014932 for ; Tue, 20 Feb 2007 01:11:53 -0500 Date: Tue, 20 Feb 2007 07:11:51 +0100 From: Luca Berra Subject: Re: [linux-lvm] LVM + Multipathing Message-ID: <20070220061150.GA3215@percy.comedia.it> References: <3nmja4-jtv.ln1@www.researchut.com> Mime-Version: 1.0 Content-Disposition: inline In-Reply-To: <3nmja4-jtv.ln1@www.researchut.com> Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" Content-Transfer-Encoding: 7bit To: linux-lvm@redhat.com On Sat, Feb 17, 2007 at 09:52:27PM +0530, Ritesh Raj Sarraf wrote: >Hi, > >I have a question regarding the combination of LVM + Multipathing in a SAN >environment. > >I have a LUN mapped to a host using iSCSI. I have two two paths to the LUN. This >setup, using multipathing, provides me failover functionality. > >My question is how does LVM react to path failures ? >In a failover environment, multipathing can take upto 120 seconds to detect that >the active path to the LUN is no more available and then switch to the >secondary path. During this 120 seconds, how does LVM react ? Does it really >sense that the device is offlined ? Or that information is never passed to LVM >and it just allows I/O to happen leaving that responsibility to the >multipathing layer ? i believe LVM does not react at all. L. -- Luca Berra -- bluca@comedia.it Communication Media & Services S.r.l. /"\ \ / ASCII RIBBON CAMPAIGN X AGAINST HTML MAIL / \