From owner-freebsd-fs@FreeBSD.ORG Thu May 17 11:17:13 2012 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id D300C1065670 for ; Thu, 17 May 2012 11:17:13 +0000 (UTC) (envelope-from gkontos.mail@gmail.com) Received: from mail-vb0-f54.google.com (mail-vb0-f54.google.com [209.85.212.54]) by mx1.freebsd.org (Postfix) with ESMTP id 80A818FC14 for ; Thu, 17 May 2012 11:17:13 +0000 (UTC) Received: by vbmv11 with SMTP id v11so2098488vbm.13 for ; Thu, 17 May 2012 04:17:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=L5N6bw9W3MEcNWDlcieLL0tkocmd5s8cq38q74oZpEE=; b=Nc+woxOomBw4dkESOvLCrIe02iJtJcFbkaZ/U7IvlRHuEAfTwFt38N5rTmwGiYyx/0 ge1DWDVGrIZ2QpziwYN9XbBHQEiDJK/Mvf5KqrtLIQ9GwQHziF4yTuQhzJmbn9fDXQTb ayOXCCT035GdDIR3rCuVLZfH3T4+LOqwc0b9UpUbkIeascdCUz4Nm6R2IQ6wQBGEk4op QSicn5/btsD4ZQnTynfROchz+KOgBaQDhihNp3qikAxOlKJkNdkcOQ/BMXDEgjfS8Ft7 /vqUZYohhzxRJ7ljyuudXkzClESmozhjCnRefYiLdQ2ZJgPN5Gaz9TopxWmPXjCToZ6z XxzA== MIME-Version: 1.0 Received: by 10.52.26.240 with SMTP id o16mr3965584vdg.20.1337253432596; Thu, 17 May 2012 04:17:12 -0700 (PDT) Received: by 10.220.8.202 with HTTP; Thu, 17 May 2012 04:17:12 -0700 (PDT) In-Reply-To: References: <20120515102206.GA53750@psconsult.nl> Date: Thu, 17 May 2012 14:17:12 +0300 Message-ID: From: George Kontostanos To: freebsd-fs@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 Subject: Re: Mirror of Raidz for data reliability X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 17 May 2012 11:17:13 -0000 On Thu, May 17, 2012 at 1:52 PM, George Kontostanos wrote: > On Thu, May 17, 2012 at 3:29 AM, Marcelo Araujo wrote: >> George, >> >>> >>> If you have 2 machines then your best bet would be HAST. >> >> >> So, why use ETHERNET if my Machine can see both JBOD? > > I was under the impression that you are talking about 2 different > physical machines. > >>> If you are worried about data replication you can always use lagg with >>> 2 or more interfaces. >> >> >> It is different than data replication. It is data protection. > > Storing the same data in 2 different locations is data protection. > > Regards > Ok, after reading more carefully your first post I realized what you are trying to do. 2 Machines, 2 different controllers. Yet interconnected. So, in a way both machines would be able to see both controllers. This is very interesting but there are some implications. 1) Suppose you manage to create a mirror consisted by drives on those different controllers. If you reboot machine #1 machine#2 might panic. It is not like loosing a drive, here we are loosing a controller. 2) Both machines have to be online and the pool has to be mounted readonly on the standby! You don't want both of them to accidentally write at the same pool. 3) HAST requires tcp to work therefore it is a no go. HAST also works in the vdev level. Therefore the resources should not be online on the standby server. Good luck, this is certainly very interesting. -- George Kontostanos Aicom telecoms ltd http://www.aisecure.net