From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx3.redhat.com (mx3.redhat.com [172.16.48.32]) by int-mx1.corp.redhat.com (8.11.6/8.11.6) with ESMTP id i5AMC0020846 for ; Thu, 10 Jun 2004 18:12:01 -0400 Received: from localhost.localdomain (app.clientdynamics.net [66.45.103.235] (may be forged)) by mx3.redhat.com (8.12.10/8.12.10) with ESMTP id i5AMBtXn022761 for ; Thu, 10 Jun 2004 18:11:55 -0400 Received: from [127.0.0.1] (localhost.localdomain [127.0.0.1]) by localhost.localdomain (8.12.11/8.12.8) with ESMTP id i5AMAuTR030295 for ; Thu, 10 Jun 2004 17:10:56 -0500 Message-ID: <40C8DC70.7050404@coremetrics.com> Date: Thu, 10 Jun 2004 17:10:56 -0500 From: Austin Gonyou MIME-Version: 1.0 Subject: Re: [linux-lvm] Multipath without round-robin? References: <40C8DB58.9090203@coremetrics.com> In-Reply-To: <40C8DB58.9090203@coremetrics.com> Content-Type: multipart/alternative; boundary="------------090806080406000701020804" 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: To: LVM general discussion and development This is a multi-part message in MIME format. --------------090806080406000701020804 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Austin Gonyou wrote: > You could just use the qlogic hba driver failover. > > ql2xfailover=1 in your rmodules.conf One caveat, if you're not running with write cache mirroring on you your volumes, then no matter md or qla failover, you may get data corruption. Some apps don't run well with it on because of the performance hit. > Jedi/Sector One wrote: > >> Hello. >> >> I'm trying to get multipath working with LVM2 (2.6.7-rc2-udm2 >> kernel) with >> an LSI storage array. >> >> The array has two FC controllers, HBAs are two identical Qlogic 2340. >> >> On the array, "preferred" controllers are assigned to each LUN. >> >> Unfortunately, it looks like dm-multipath always does round-robin load >> balancing. >> >> The result is that the array fills up the (SANtricity) error log with >> messages like "LUN was accessed through the wrong controller". >> >> Is there any way to keep failover abilities without load balancing? >> >> Best regards, >> >> -Frank. >> >> --------------090806080406000701020804 Content-Type: text/html; charset="iso-8859-15" Content-Transfer-Encoding: quoted-printable Austin Gonyou wrote:
You could just use the qlogic hba driver failover.

ql2xfailover=3D1 in your rmodules.conf

One caveat, if you're not running with write cache mirroring on you your volumes, then no matter md or qla failover, you may get data corruption. Some apps don't run well with it on because of the performance hit.

Jedi= /Sector One wrote:
[linux-lvm] Multipath without round-robin?

=EF=BF=BD Hello.
=EF=BF=BD
=EF=BF=BD I'm trying to get multipath working with LVM2 (2.6.7-rc2-udm2 kernel) with
an LSI storage array.

=EF=BF=BD The array has two FC controllers, HBAs ar= e two identical Qlogic 2340.
=EF=BF=BD
=EF=BF=BD On the array, "preferred" controllers are as= signed to each LUN.
=EF=BF=BD
=EF=BF=BD Unfortunately, it looks like dm-multipath al= ways does round-robin load
balancing.

=EF=BF=BD The result is that the array fills up the (SANtricity) error log with
messages like "LUN was accessed through the wrong controller".

=EF=BF=BD Is there any way to keep failover abiliti= es without load balancing?
=EF=BF=BD
=EF=BF=BD Best regards,
=EF=BF=BD
=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD= -Frank.
=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=EF=BF=BD=


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