From owner-freebsd-questions@FreeBSD.ORG Sun Jun 29 21:57:40 2008 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id BB87A1065672 for ; Sun, 29 Jun 2008 21:57:40 +0000 (UTC) (envelope-from prad@towardsfreedom.com) Received: from pd2mo3so.prod.shaw.ca (idcmail-mo1so.shaw.ca [24.71.223.10]) by mx1.freebsd.org (Postfix) with ESMTP id 97C2D8FC1D for ; Sun, 29 Jun 2008 21:57:40 +0000 (UTC) (envelope-from prad@towardsfreedom.com) Received: from pd3mr4so.prod.shaw.ca (pd3mr4so-qfe3.prod.shaw.ca [10.0.141.180]) by l-daemon (Sun ONE Messaging Server 6.0 HotFix 1.01 (built Mar 15 2004)) with ESMTP id <0K3800J4BVN3RE30@l-daemon> for freebsd-questions@freebsd.org; Sun, 29 Jun 2008 15:57:03 -0600 (MDT) Received: from pn2ml4so.prod.shaw.ca ([10.0.121.148]) by pd3mr4so.prod.shaw.ca (Sun Java System Messaging Server 6.2-7.05 (built Sep 5 2006)) with ESMTP id <0K3800BBOVN2K700@pd3mr4so.prod.shaw.ca> for freebsd-questions@freebsd.org; Sun, 29 Jun 2008 15:57:03 -0600 (MDT) Received: from gom.home ([70.67.160.176]) by l-daemon (Sun ONE Messaging Server 6.0 HotFix 1.01 (built Mar 15 2004)) with ESMTP id <0K3800ASPVN2AO10@l-daemon> for freebsd-questions@freebsd.org; Sun, 29 Jun 2008 15:57:02 -0600 (MDT) Received: from gom.home (localhost [127.0.0.1]) by gom.home (Postfix) with ESMTP id 410F8B842 for ; Sun, 29 Jun 2008 14:56:57 -0700 (PDT) Date: Sun, 29 Jun 2008 14:56:57 -0700 From: prad To: freebsd-questions@freebsd.org Message-id: <20080629145657.05b7a462@gom.home> MIME-version: 1.0 X-Mailer: Claws Mail 3.3.1 (GTK+ 2.12.1; i386-portbld-freebsd7.0) Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7bit Subject: second pre-emptive raid: stripes and the os X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 29 Jun 2008 21:57:40 -0000 based on the excellent ideas from the first pre-emptive raid thread we have been considering raid1+0 or raid5 for our server, but we need to gain a better understanding of striping. the mirror concept was easy particularly through dru's Using Software RAID-1 with FreeBSD: http://www.onlamp.com/pub/a/bsd/2005/11/10/FreeBSD_Basics.html?page=1 the stripe idea is creating some issues. having gone through both geom and vinum sections of the handbook, we are confused as to just how stripes fit in with the os. what we have found on the web sofar is this article on the freebsdwiki: http://www.freebsdwiki.net/index.php/RAID0,_Software,_How_to_setup both this article and the geom docs require an installed os, from which you create the striped device. so if we had 4 drives da0-3, we could install the os on da0 and then create a stripe /dev/stripe/st0 with da1-3. however, there would be no os on there (and most of da0 would be empty). (i suppose you can dd stuff onto st0, but that seems a bit strange.) so in a straight striped situation with 4 physical drives, how can you get the os on there? where does it reside? is it supposed to be striped across the 4 drives? or is this the wrong way to look at it. should we be directing our thoughts to striping across partitions that we create over various drives after the os has been installed on a small part of the first drive? is raid only for data or does the os get raided too? -- In friendship, prad ... with you on your journey Towards Freedom http://www.towardsfreedom.com (website) Information, Inspiration, Imagination - truly a site for soaring I's