From owner-freebsd-current@FreeBSD.ORG Sun Nov 20 00:41:47 2005 Return-Path: X-Original-To: freebsd-current@FreeBSD.org Delivered-To: freebsd-current@FreeBSD.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id C7B6816A41F; Sun, 20 Nov 2005 00:41:47 +0000 (GMT) (envelope-from dwhite@gumbysoft.com) Received: from carver.gumbysoft.com (carver.gumbysoft.com [66.220.23.50]) by mx1.FreeBSD.org (Postfix) with ESMTP id 924EA43D46; Sun, 20 Nov 2005 00:41:47 +0000 (GMT) (envelope-from dwhite@gumbysoft.com) Received: by carver.gumbysoft.com (Postfix, from userid 1000) id 7947E72DD4; Sat, 19 Nov 2005 16:41:47 -0800 (PST) Received: from localhost (localhost [127.0.0.1]) by carver.gumbysoft.com (Postfix) with ESMTP id 76F9872DCB; Sat, 19 Nov 2005 16:41:47 -0800 (PST) Date: Sat, 19 Nov 2005 16:41:47 -0800 (PST) From: Doug White To: Alexander Leidinger In-Reply-To: <20051119165631.093b90b9@Magellan.Leidinger.net> Message-ID: <20051119163635.E88861@carver.gumbysoft.com> References: <20051119162854.2656096a@Magellan.Leidinger.net> <13727.1132414598@critter.freebsd.dk> <20051119165631.093b90b9@Magellan.Leidinger.net> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: delphij@delphij.net, Poul-Henning Kamp , freebsd-current@FreeBSD.org, Robert Watson , Brian Candler Subject: Re: Logical volume management X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 20 Nov 2005 00:41:47 -0000 On Sat, 19 Nov 2005, Alexander Leidinger wrote: > You can define more than one resource pool with ZFS, and as I did > understand it, the pools are distinct. So if you assign disc1 and disc2 > to poolA and disc3 and disc4 to poolB, and you assign just one FS to > each pool, you still have the same separation like in vinum or > g{mirror,raid3,stripe}. You just have a more complex distribution > algorithm. However the ZMU layer doesn't allow you to stack transforms, so you can't do RAID10 by stacking a stripe transform on a mirror. Score a point for GEOM and the oldie-but-goodie SDS. :) The ZFS code and architecture docs imply that the volume-management aspects and the filesystem are abstracted from one another and are bundled only for administrative simplicity. If they wanted to, the ZMU could have been a separate component and you could have layered UFS on top of it. Most of the code is available through OpenSolaris if you want to see how its done. -- Doug White | FreeBSD: The Power to Serve dwhite@gumbysoft.com | www.FreeBSD.org