From owner-freebsd-geom@FreeBSD.ORG Wed Nov 10 18:29:24 2010 Return-Path: Delivered-To: freebsd-geom@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0E001106564A for ; Wed, 10 Nov 2010 18:29:24 +0000 (UTC) (envelope-from modulok@gmail.com) Received: from mail-ww0-f50.google.com (mail-ww0-f50.google.com [74.125.82.50]) by mx1.freebsd.org (Postfix) with ESMTP id 986A38FC2B for ; Wed, 10 Nov 2010 18:29:23 +0000 (UTC) Received: by wwi18 with SMTP id 18so94527wwi.31 for ; Wed, 10 Nov 2010 10:29:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:cc:content-type; bh=WM+pAQdkV1RI2wlisjmiWbPCUiTH3Wf9t/F3E/SmI00=; b=Yxfmyv8PF4tz8zztHUVTPPlR958XAXamIRdsRnJfX9PYJTWjOBJbnOqNmeGrCr2zwb DkwijCrzjTDrxVsB5ktEWqVEnMRAslfKBmFn+Qx2o8yQn7ENVZlrYQJowE0EypahIBKl GbfjOClt+AccgAXjTAcZbYiV1OllquHBh3Agw= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=neWpG9PQS5H4wGcczy9GmbZgjqnnCiW2oCH2U7VsdLsb1IBqSMnD9HMUNvZbAXhvJe VK8glX52paz7hP6yBoWQzp6jGg9M3mnwkvoY63sWaIWR/nQ4eFaIHP0w9uf7rabqfD8x DRtJ/WqamK2GziwPHrIo03qeTCXrmPBAj/VdE= MIME-Version: 1.0 Received: by 10.227.72.196 with SMTP id n4mr8651636wbj.153.1289411871585; Wed, 10 Nov 2010 09:57:51 -0800 (PST) Received: by 10.227.138.12 with HTTP; Wed, 10 Nov 2010 09:57:51 -0800 (PST) In-Reply-To: <4CDAC7E2.5050309@cyanide-studio.com> References: <4CDAC7E2.5050309@cyanide-studio.com> Date: Wed, 10 Nov 2010 10:57:51 -0700 Message-ID: From: Modulok To: Bastien Semene Content-Type: text/plain; charset=ISO-8859-1 Cc: freebsd-geom@freebsd.org Subject: Re: Newbie RAID 0 question X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 10 Nov 2010 18:29:24 -0000 > Is there a way to add a component to an existing RAID 0 array ? Probably not. I say "probably" as a personal disclaimer, but I'm pretty confident the answer is a resounding 'no'. RAID 0 is a pure striped arrangement with the goal of increasing throughput at the cost of reliability. If any single disk fails, all data is gone. The reason for this, is that data is literally 'striped' across the two, (or more) disks in alternating blocks (or whatever stripe size you configure). You can't simply append a third disk to the array and still have alternating blocks between the three disks. All data would need to be shuffled around to be re-distributed across all disks in the array. I know of no software which can do this on a functioning array. (Not saying it's impossible, just saying 'as far as I know'.) You must dump all data to a backup server, create a new array, and copy the data back over. Essentially, you have to reconstruct the array from scratch. -Modulok-