From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (mx1.redhat.com [172.16.48.31]) by int-mx1.corp.redhat.com (8.12.11.20060308/8.12.11) with ESMTP id k786pGmA014091 for ; Tue, 8 Aug 2006 02:51:16 -0400 Received: from dark-templar.advansoft.us ([166.70.63.214]) by mx1.redhat.com (8.12.11.20060308/8.12.11) with ESMTP id k786pDUW031591 for ; Tue, 8 Aug 2006 02:51:15 -0400 Received: from [10.3.219.138] (72-254-42-65.client.stsn.net [72.254.42.65]) by dark-templar.advansoft.us (Postfix) with ESMTP id 909B46812E for ; Tue, 8 Aug 2006 00:51:07 -0600 (MDT) From: "Lamont R. Peterson" Subject: Re: [linux-lvm] Running LVM on shared LUNs Date: Tue, 8 Aug 2006 00:50:36 -0600 References: <1154987972.16651.28.camel@localhost.localdomain> In-Reply-To: <1154987972.16651.28.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart2304038.59QIrMFZNj"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Message-Id: <200608080050.42004.peregrine@openbrainstem.net> 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 --nextPart2304038.59QIrMFZNj Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Monday 07 August 2006 03:59pm, Joshua Aune wrote: > I have two systems that are connected to a SAN. The SAN is exporting > the same 4 luns to each system (/dev/sd[b,c,d,e]). Under normal > operation system1 will combine sdb with sdc into a vg and system2 will > combine sdd with sde into a vg with both vgs consisting of one large lv > and one small lv. After the system is configured there will be no > modifications made to the LVM configuration. LVM is configured on one > node and then copied over to the second node. > > The million dollar question is, can system1 and system2 simultaneously > have both of the VGs active without hosing any data? As I understand it, only if you are using a filesystem that supports cluste= red=20 operations, like GFS. > I am not trying to have the same filesystem mounted simultaneously, just > have the LVs available simultaneously for failover needs In that case, as long as you have some heartbeat or something that lets you= =20 know when the one system needs to take over the other's PVs. The trick her= e=20 is that if you lose your network connection, but the box is still accessing= =20 data on the LUNs, that could become problematic. Maybe a tiny little share= d=20 GFS thing would allow your boxes a place to write some status info (a=20 custom "heartbeat", if you will) so that a network disconnect or other issu= e=20 won't cause false alarms. Probably best to just use GFS. > I know that this sort of config can be done with the GFS pool volume > manger but I have been told that many other VMs don't support this > behavior.... /me shrugs Not sure about that as I don't have any SAN to play with :( . Never tried = it. =2D-=20 Lamont R. Peterson =46ounder [ http://blog.OpenBrainstem.net/peregrine/ ] GPG Key fingerprint: 0E35 93C5 4249 49F0 EC7B 4DDD BE46 4732 6460 CCB5 ___ ____ _ _ / _ \ _ __ ___ _ __ | __ ) _ __ __ _(_)_ __ ___| |_ ___ _ __ ___ | | | | '_ \ / _ \ '_ \| _ \| '__/ _` | | '_ \/ __| __/ _ \ '_ ` _ \ | |_| | |_) | __/ | | | |_) | | | (_| | | | | \__ \ || __/ | | | | | \___/| .__/ \___|_| |_|____/|_| \__,_|_|_| |_|___/\__\___|_| |_| |_| |_| Intelligent Open Source Software Engineering [ http://www.OpenBrainstem.net/ ] --nextPart2304038.59QIrMFZNj Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (GNU/Linux) iD8DBQBE2DRBvkZHMmRgzLURAiMgAJ9iSY5IwT3DSRwcBQTWGVC8MYULBQCgguyU n+5mfGTpoayVLJGP1WaYO0U= =p+U7 -----END PGP SIGNATURE----- --nextPart2304038.59QIrMFZNj--