From owner-freebsd-fs@FreeBSD.ORG Mon Jun 4 20:26:24 2012 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 3FB221065680; Mon, 4 Jun 2012 20:26:24 +0000 (UTC) (envelope-from kayasaman@gmail.com) Received: from mail-ey0-f182.google.com (mail-ey0-f182.google.com [209.85.215.182]) by mx1.freebsd.org (Postfix) with ESMTP id 9CBF78FC16; Mon, 4 Jun 2012 20:26:23 +0000 (UTC) Received: by eaac13 with SMTP id c13so1078344eaa.13 for ; Mon, 04 Jun 2012 13:26:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; bh=AMundgGb84eEMSTGRgbjIdsfTOc3ohgZfGLABaw0hVQ=; b=ZlWGsL6A9slwBxlOOR07RlxOBhn5fUwEbIDn2+ZrydtX6J6a77LDTKelK2E9ddgJqH csIjrb4lTZzhJfxS16H5a0/FDEfBID4HK9javPv7fmHUDkmMA66ztUPVG01IPeVPRwGv fHv8YfKkOgRKlkAeRMDHSPYQjyRhYIVxr34i6KLF/Dej7vytyLGhHOA4L5bTbsmTpmH4 zFyZSfkQSc1tYzvEOfYQMjgr8j7ESiAcxZfMuHUtqXHUFuWkdBKecG9sZQpQnulO1/S+ m6oHEaxunnA9yp5ZbEO+ega6JZew3k/BSJQ9z2pUZLYjDM3fUfavNRwE0Lwhn0qHxMu9 5tFQ== Received: by 10.14.96.70 with SMTP id q46mr5748820eef.231.1338841577545; Mon, 04 Jun 2012 13:26:17 -0700 (PDT) Received: from X220.optiplex-networks.com (81-178-2-118.dsl.pipex.com. [81.178.2.118]) by mx.google.com with ESMTPS id u7sm41001322eeb.7.2012.06.04.13.26.15 (version=SSLv3 cipher=OTHER); Mon, 04 Jun 2012 13:26:16 -0700 (PDT) Message-ID: <4FCD19E6.1010802@gmail.com> Date: Mon, 04 Jun 2012 21:26:14 +0100 From: Kaya Saman User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Matthew Seaman References: <4FCD13CF.3010406@gmail.com> <4FCD17C6.5020503@FreeBSD.org> In-Reply-To: <4FCD17C6.5020503@FreeBSD.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-fs@FreeBSD.org Subject: Re: Using ZFS as RAID0 - disk offline question 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: Mon, 04 Jun 2012 20:26:24 -0000 On 06/04/2012 09:17 PM, Matthew Seaman wrote: > On 04/06/2012 21:00, Kaya Saman wrote: >> in ZFS when using a simple RAID 0 style array is there a way to recover >> a pool after a disk has gone down? > No. RAID0 has no resilience to disk failure. That's why things like > RAID1, RAID10, RAIDz, RAIDz2 exist: so that your data will survive > failure of some number of the drives it is stored on. > > Make sure you have good backups, basically. > > Cheers > > Matthew > Thanks for the responses! I wasn't actually meaning recovering data on the 'downed' disk but on the disk that was still online...... You see if say a system board fails and both devices are named /dev/ad4 and /dev/ad5 then a new system board gets put in and the device names changed to /dev/ad12 and /dev/ad13 my question is will the ZPOOL still exist? Will ZFS be intelligent enough to pick up the new device names via the disk ID's? Additionally if /dev/ad5 goes down, is it possible to keep using /dev/ad4 which is part of the 'downed' pool...?? Or would one need to replace the disk ad5 then the pool comes up again with only the information on ad4?? This is what I was trying to get at and sorry if I didn't understand 100% the direction of the responses! As in if you meant that the information of on /dev/ad5 will be lost - I do understand this :-) Regards, Kaya