From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1MGbYV-0001QL-Vu for garchives@archives.gentoo.org; Tue, 16 Jun 2009 16:30:40 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id F03DDE0349; Tue, 16 Jun 2009 16:30:38 +0000 (UTC) Received: from mail-bw0-f223.google.com (mail-bw0-f223.google.com [209.85.218.223]) by pigeon.gentoo.org (Postfix) with ESMTP id A5761E0349 for ; Tue, 16 Jun 2009 16:30:38 +0000 (UTC) Received: by bwz23 with SMTP id 23so3742968bwz.34 for ; Tue, 16 Jun 2009 09:30:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:date:from:to:subject :message-id:in-reply-to:references:x-mailer:mime-version :content-type:content-transfer-encoding; bh=zMm7jP1S+ZnnZT5a6Nm9h0vkVMBmoZoIUxnobzIKNsU=; b=EXwaxTmTXC72S0McBHbWOEOjpznH9bo3/+ndDovGWB40bJ1SGlAaLypgn+fyk93Pcd ejsCB4czJ/2w3SyoS2DhKmcM7zJgCg0lvstl2hDqQiOGWgnmh7AlflJCAITn+8B2UX2A AoEGFoECc79v/G3DekkaQrRa0Ai0XjR3vcF0c= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:subject:message-id:in-reply-to:references:x-mailer :mime-version:content-type:content-transfer-encoding; b=jlw1MJRFjtYTFx4VPjRWe02p/1iB32sz8F5EQLvFx6LBIP15jqgMQ06UYuD1DgC7/I XEK+HVU35kiBER8Bd5XHVJock4hRLZdQ+1W0KIKmxDpo6hK+hkv/CUr1CCOLRWGiOub/ ZbL9PC4959H9WChUOdz/vPDdPoVp7YT/5rIQ4= Received: by 10.103.213.10 with SMTP id p10mr2984134muq.132.1245169837876; Tue, 16 Jun 2009 09:30:37 -0700 (PDT) Received: from ilievnet.com ([84.21.204.200]) by mx.google.com with ESMTPS id y2sm288494mug.43.2009.06.16.09.30.36 (version=TLSv1/SSLv3 cipher=RC4-MD5); Tue, 16 Jun 2009 09:30:37 -0700 (PDT) Date: Tue, 16 Jun 2009 19:30:35 +0300 From: Daniel Iliev To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] [OT] RAID 1 over network Message-ID: <20090616193035.1fda03a6@ilievnet.com> In-Reply-To: <1245160717.11720.4.camel@hspc32.informatik.uni-stuttgart.de> References: <20090616124046.7e484352@symbox> <20090616185856.61bd4ee3@coercion> <20090616164510.57f049c7@ilievnet.com> <1245160717.11720.4.camel@hspc32.informatik.uni-stuttgart.de> X-Mailer: Claws Mail 3.7.1 (GTK+ 2.14.7; x86_64-pc-linux-gnu) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Archives-Salt: d84fed68-2e7d-480e-b7f6-580e73477c17 X-Archives-Hash: d3282e3b894dcad5e7eaeac3f61d2aea On Tue, 16 Jun 2009 15:58:37 +0200 Philipp Riegger wrote: > > On Tue, 2009-06-16 at 16:45 +0300, Daniel Iliev wrote: > > DRBD is HA solution which is achieved by switching the role of the > > nodes in case the "active node" goes offline. I think DRBD is not > > meant for the schema OP has described, because only the "active > > node" is accessible via FS. DRBD works between the FS and block > > device layers. It catches the FS writes from the active node and > > sends them over the network. DRBD on the backup node receives those > > and replicates them directly to the disk driver. Thus you can't > > have mounted FS on the backup node. If the active node goes > > offline, the backup node takes over which means DRBD switches roles > > and the FS has to be mounted afterwards. > > But that might be a good solution with 2.6.30, NFS and FSCACHE. > Sorry, perhaps I'm missing something, but I couldn't understand the solution you had in mind. I'm just saying that the only scenario I have some experience with is DRBD + ext3 and it won't work for load balancing. If "LAMP A" and "LAMP B" as shown on the OP's schema were connected via DRBD + a conventional FS (ext/xfs/reiser/etc.), then only one of those systems would be able to serve client requests at a given moment. -- Best regards, Daniel