From mboxrd@z Thu Jan 1 00:00:00 1970 From: Molle Bestefich Subject: Re: Fwd: Linux MD raid5 and reiser4... Any experience ? Date: Mon, 9 Jan 2006 09:00:06 +0100 Message-ID: <62b0912f0601090000l8eb613ci4c3b237805c77182@mail.gmail.com> References: <17341.8541.33899.167524@smtp.charter.net> <17341.27534.41206.232976@smtp.charter.net> <20060106104931.GB20546@atc5.vermine.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: In-Reply-To: <20060106104931.GB20546@atc5.vermine.org> Content-Disposition: inline Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Andre Majorel wrote: > With LVM, you can create a snapshot of the block device at any > time, mount the snapshot read-only (looks like another block > device) and backup that. Ensuring consistency at application level > is still up to you but at least, if that involves stopping > services, the unavailability window is greatly reduced. Hmm. And 1 out of 10 times it will completely *nuke* your data. Not just the new snapshot you've just created, mind you, but also the volume you're snapshotting. I'm talking from experience. That's a "stable" version of LVM I'm talking about, and it was a fresh install from the most recent RedHat distro too. A week ago I compiled my own version of kernel/device-mapper tools/lvm from the newest sources I could find. It didn't trash my data, but 1/4 times it created an unusable snapshot. I've personally burn-in tested the hardware and there's absolutely no problems there. It's a standard server from HP, naturally not overclocked or anything like that. It's apparently a known fact that the code is wildly unstable, so stay away from it if you happen to like your data :-).