From owner-freebsd-fs@FreeBSD.ORG Mon Jun 4 20:48:05 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 8E1FB106567D for ; Mon, 4 Jun 2012 20:48:05 +0000 (UTC) (envelope-from joh.hendriks@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 1A4EF8FC15 for ; Mon, 4 Jun 2012 20:48:04 +0000 (UTC) Received: by eaac13 with SMTP id c13so1083941eaa.13 for ; Mon, 04 Jun 2012 13:48:04 -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=w8AAAysMxMKMCrPflrBBRZ/OMqImaTTcQ+un5s7CvkY=; b=D5cbGOpXuVeDuc4+N5nDz7mcHifEGzwdACWKvPh/z1iBzrBZmkzMJrKXYgRXkQIZnw h8GIvIedJu4npzRBT0q0J7JiDB1Rx9s+2aijm2NwWwBl7aYWuhyBDxAWjaZJo6VqOiSU cIFT2pGXeauKnXwJC8gaKF3XKh8qlXbz8wUMCl7goTNhY66LAiupPqi9Z6oSWScb3kbQ +te+onAGf4Ev7UyKI+Hge2a6Fr3D9PjvFIk0D3Zk0Nw0w+MYWf2ACSMvmJKG3KQc9N83 ING3LutxoTP0MQMxCfWMWo2ZML3qQDVLMXLee9aemX2flCLqxohooBAfJE8M/aj+nI0m wxIA== Received: by 10.14.119.196 with SMTP id n44mr6725099eeh.29.1338842884117; Mon, 04 Jun 2012 13:48:04 -0700 (PDT) Received: from [192.168.1.14] (5ED0E470.cm-7-1d.dynamic.ziggo.nl. [94.208.228.112]) by mx.google.com with ESMTPS id c51sm41141480eei.12.2012.06.04.13.48.02 (version=SSLv3 cipher=OTHER); Mon, 04 Jun 2012 13:48:02 -0700 (PDT) Message-ID: <4FCD1F00.5080805@gmail.com> Date: Mon, 04 Jun 2012 22:48:00 +0200 From: Johan Hendriks User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Kaya Saman References: <4FCD13CF.3010406@gmail.com> <4FCD17C6.5020503@FreeBSD.org> <4FCD19E6.1010802@gmail.com> In-Reply-To: <4FCD19E6.1010802@gmail.com> 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 20:48:05 -0000 Kaya Saman schreef: > 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 > _______________________________________________ > freebsd-fs@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" you can not loose a disk from a raid0 period. To put it simple, your files are split in half, one part is copied to disk 1 and the other part on disk2 . So without the two copies no files, no data. If device names changes because of a hardware change, the pool schould be importable. But both disks need to be there. Raid0 should be avoided if possible, better add one disk extra and create a raidz. regards Johan Hendriks