From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tim Subject: Re: [linux-lvm] has anyone used LVM in a HA cluster? Message-ID: <20020513073337.A31182@connectlive.com> References: <20020510072608.GA1001@tykepenguin.com> <1021071171.17474.44.camel@UberGeek> <671160000.1021077884@[192.168.200.4]> <20020511192728.GB3125@colombina.comedia.it> <3CDF8482.7010109@lausch.at> Mime-Version: 1.0 Content-Disposition: inline In-Reply-To: <3CDF8482.7010109@lausch.at>; from mla@lausch.at on Mon, May 13, 2002 at 11:16:50AM +0200 Sender: linux-lvm-admin@sistina.com Errors-To: linux-lvm-admin@sistina.com Reply-To: linux-lvm@sistina.com List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: Date: Mon May 13 07:33:01 2002 List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-lvm@sistina.com > And make sure the daemons are running in the real time scheduler class. > There exists a state, commomly refered to as "split brain", where the > nodes of a cluster "think" the other one is down, which is not the fact. > Reason for this may be that the load is so high, that the heartbeat > daemon is not scheduled in time to answer the requests (it happened to > me with a commercial product). then both nodes mount the filesystem. > Usually the inital fsck (or log replay or whatever) is enough to destroy > the filesystem beyond repair. But all these things are in no way LVM > specific, so it works. Or don't, and buy a power supply that you can control from serial, and do so -- STONITH, it's called -- Shoot The Other Node In The Head. Once the power is off, there is no danger of fsck'ing... It's a rather elegant way to solve that problem, IMHO. We're going that route. -- "The most valuable piece of equipment in the darkroom is the trash can." --Ansel Adams