From owner-freebsd-questions@FreeBSD.ORG Sat Feb 22 20:19:54 2014 Return-Path: Delivered-To: questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 4E3F6692; Sat, 22 Feb 2014 20:19:54 +0000 (UTC) Received: from h3lix.wtfayla.net (helix.wtfayla.net [24.105.170.68]) (using TLSv1 with cipher ADH-CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 047601969; Sat, 22 Feb 2014 20:19:49 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by h3lix.wtfayla.net (Postfix) with ESMTP id 1086584949; Sat, 22 Feb 2014 15:18:48 -0500 (EST) Received: from h3lix.wtfayla.net ([127.0.0.1]) by localhost (h3lix.wtfayla.net [127.0.0.1]) (maiad, port 10024) with ESMTP id 60739-01; Sat, 22 Feb 2014 15:18:47 -0500 (EST) Received: from helix.wtfayla.net (helix.wtfayla.net [24.105.170.68]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by h3lix.wtfayla.net (Postfix) with ESMTPS id 927D884473; Sat, 22 Feb 2014 15:18:47 -0500 (EST) Date: Sat, 22 Feb 2014 15:18:47 -0500 (EST) From: freebsd@fongaboo.com X-X-Sender: fongaboo@helix.wtfayla.net To: dteske@FreeBSD.org Subject: RE: ZFS on Hardware RAID controller In-Reply-To: <101701cf2da1$8f47ddb0$add79910$@FreeBSD.org> Message-ID: References: <0fdd01cf2d29$dca0aba0$95e202e0$@FreeBSD.org> <4e4aa28301cedd61cb5693e79a90d0ab@dweimer.net> <0fdf01cf2d34$65d9de00$318d9a00$@FreeBSD.org> <87679f0a7789f01ad66b3c2ae55e3006@dweimer.net> <101101cf2d97$d708e630$851ab290$@FreeBSD.org> <101701cf2da1$8f47ddb0$add79910$@FreeBSD.org> User-Agent: Alpine 2.00 (BSF 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Mailman-Approved-At: Sun, 23 Feb 2014 00:47:27 +0000 Cc: daver@vicor.com, questions@freebsd.org, owner-freebsd-questions@freebsd.org, 'Devin Teske' X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 22 Feb 2014 20:19:54 -0000 So I think it's fair to say that there is some ambiguous information out there about the definition of JBOD. So, without worrying about settling the discrepency over nomenclature, is it fair to say that... If I am planning to use ZFS on a machine where the drive controller happens to be one that can be configured for some combination of HARDWARE RAID... I should configure it so that it does not concatenate/span/combine the drives in any way at the hardware level. I need to configure it as if it wasn't even a RAID controller, but rather in a configuration where the motherboard/filesystem/OS will initially see each physical drive as its own volume. TRUTH? Thanx FONG On Wed, 19 Feb 2014, dteske@FreeBSD.org wrote: > Re: JBOD... > > I think it's very telling that when Google gives you > the description of JBOD, it actually comes from the > Wikipedia, but ... it doesn't include the [misleading] > statement about the [optional] act of joining the > disks. > > Google's Definition: > Just a Bunch Of Disks. A collection of hard disks that > aren't configured according to RAID; A hard disk > enclosure for several disks, especially one lacking a > RAID controller > Source: http://en.wiktionary.org/wiki/JBOD > > Definition from > JBOD (abbreviated from "just a bunch of disks") is an > architecture using multiple hard drives, but not in a > RAID configuration, thus providing neither redundancy > nor performance improvements. Hard drives *may be* > handled independently as separate logical volumes, or > they *may be* combined into a single logical volume > using a volume manager like LVM; such [optionally > combined] volumes are usually called "spanned".[2] > > I added the *'s around "may be" and also added the > "[optionally combined]" texts to help clarify that for > you. And I would go on to further say that the LVM > volume manager used to combine the JBOD-access > devices is not part of nor has any relation to said > JBOD access. JBOD is a means of exporting the disks > to the volume manager whose use is optional. > -- > Devin > > _____________ > The information contained in this message is proprietary and/or confidential. If you are not the intended recipient, please: (i) delete the message and all copies; (ii) do not disclose, distribute or use the message in any manner; and (iii) notify the sender immediately. In addition, please be aware that any message addressed to our domain is subject to archiving and review by persons other than the intended recipient. Thank you. >