From owner-freebsd-scsi@FreeBSD.ORG Mon Jul 30 21:16:48 2012 Return-Path: Delivered-To: freebsd-scsi@freebsd.org Received: by hub.freebsd.org (Postfix, from userid 821) id 591ED106566B; Mon, 30 Jul 2012 21:16:48 +0000 (UTC) Date: Mon, 30 Jul 2012 21:16:48 +0000 From: John To: Matyee Message-ID: <20120730211648.GA73061@FreeBSD.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i Cc: freebsd-scsi@freebsd.org Subject: Re: Multipath iSCSI X-BeenThere: freebsd-scsi@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SCSI subsystem List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 30 Jul 2012 21:16:48 -0000 ----- P??ter Szab??'s Original Message ----- > Dear *, > > I have started to build a HA system. It runs a postgresql cluster with > two nodes (master and hot stand-by, FreeBSD 9.0, postgresl 9.1). The > storage for the database is provided by 2 separate systems (FreeBSD > 9.0, iSCSI target, over ZFS). For the maximum redundancy I would like > to use multipathing on the DB nodes. For me the best would be if the 2 > DB nodes and the 2 storage nodes are all FreeBSD. > > Now I have 4 installed FreeBSD 9.0, iSCSI targets are in place, and > the database nodes uses the exported targets as a storage. What is > left is the multipath part. > > I have search a lot in this topic, but now I am really confused. I > found some mails from this mailing list, the problem was the same, and > there was no solution, but the mails are quite old (FreeBSD 7.3). I > checked gmultipath, but it seems it is not the solution. > > Does FreeBSD support iSCSI multipath currently, or should I change the > OS under the database nodes from FreeBSD to some linux distribution. I > found a lot of working configuration for linux and iSCSI multipathing. Hi, This may not be the answer you're looking for. iscontrol TargetName=disk1_net1 TargetAddress=... iscontrol TargetName=disk1_ne12 TargetAddress=... You now have access to the same lun via two different paths. Now create a gmultipath entity (if the above came in as da1 & 2): gmultipath label -Av MULTIPATH /dev/da1 /dev/da2 The above should create: /dev/multipath/MULTIPATH which should provide the characteristics you're looking for. The -A option creates the device in active/active mode. Good Luck, John > Cheers, > > Matyee