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 1MGYyR-00070Z-48 for garchives@archives.gentoo.org; Tue, 16 Jun 2009 13:45:15 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 705DAE0435; Tue, 16 Jun 2009 13:45:13 +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 23E8DE0435 for ; Tue, 16 Jun 2009 13:45:13 +0000 (UTC) Received: by bwz23 with SMTP id 23so3617009bwz.34 for ; Tue, 16 Jun 2009 06:45:12 -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=55r6gOwxEagww61a0rANSbIq8zIwcwUjLG5+pRqu9xk=; b=XXhue+XiMtcvdjEZwk7PDysV0T0ECVWBYjGJk1425Dv0YYJpdTXDYciRO2J7wWKJa/ pGfNchJ23+cesjSW84p5gAGtButrn7/ncSWVimdyA4n4z6IbpZkKaeX11XSbri6pxcqH hdRldQckO/QaxcWMMFCSIO+gdcOvsJFqC11GU= 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=ZHgObaqrZ+4nZgnGPa/BLLMHzkAlZhIL96vX5kweanojWzxbPM0DK/VcS+UTWHUXHW NunAxC9aiyiUXBaoFEzlAaiXkeEBhE9wlGON4/CvLyeUnQBiLu4EyxkVqyMd888lTZhP 416SRz4l2vhdgBy+xL0DNi4SnZ/wHH/TSZC7U= Received: by 10.103.24.11 with SMTP id b11mr4462207muj.133.1245159912351; Tue, 16 Jun 2009 06:45:12 -0700 (PDT) Received: from ilievnet.com ([84.21.204.200]) by mx.google.com with ESMTPS id j10sm5220169mue.29.2009.06.16.06.45.11 (version=TLSv1/SSLv3 cipher=RC4-MD5); Tue, 16 Jun 2009 06:45:11 -0700 (PDT) Date: Tue, 16 Jun 2009 16:45:10 +0300 From: Daniel Iliev To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] [OT] RAID 1 over network Message-ID: <20090616164510.57f049c7@ilievnet.com> In-Reply-To: <20090616185856.61bd4ee3@coercion> References: <20090616124046.7e484352@symbox> <20090616185856.61bd4ee3@coercion> 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: f960a101-1bf7-4a7c-abd5-e70d7e3c41c0 X-Archives-Hash: 2b42a9d4d2a4a6e304b92a191bec42d5 On Tue, 16 Jun 2009 18:58:56 +0600 Mike Kazantsev wrote: > On Tue, 16 Jun 2009 12:40:46 +0200 > Renat Golubchyk wrote: > > > Hi all! > > > > Short: > > What is the best way to setup something similar to RAID 1 over a > > WAN? > > ... > > > One purpose of the setup is to have data redundancy. Thus we have to > > ensure that the data is replicated in a timely manner. Replicating > > MySQL data is not difficult. The problem is the file system data > > like uploaded documents and pictures. We can monitor changes in the > > file system and initiate rsync to copy files over the network, but > > I think it's not a good solution. What we are after is a network > > equivalent of RAID 1. Are there any viable solutions that could > > work over a WAN? > > If replication after file is completely hit the disk is not acceptable > either because files are quite large or have to be really synchronous > then I'll second DRBD-with-HA-cluster-fs suggestion. > 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. -- Best regards, Daniel