From owner-freebsd-fs@FreeBSD.ORG Fri Aug 22 10:02:02 2003 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 5BC3616A4BF for ; Fri, 22 Aug 2003 10:02:02 -0700 (PDT) Received: from out-mx1.crosswinds.net (out-mx1.crosswinds.net [216.18.117.38]) by mx1.FreeBSD.org (Postfix) with ESMTP id B094443FF3 for ; Fri, 22 Aug 2003 10:02:01 -0700 (PDT) (envelope-from tony@crosswinds.net) Received: from admin.crosswinds.net (out-mx1.crosswinds.net [216.18.117.38]) by out-mx1.crosswinds.net (Postfix) with ESMTP id 4ACB62C577; Fri, 22 Aug 2003 13:02:01 -0400 (EDT) Received: by admin.crosswinds.net (Postfix, from userid 1001) id 0CA403F0B; Fri, 22 Aug 2003 13:02:01 -0400 (EDT) Date: Fri, 22 Aug 2003 13:02:00 -0400 From: Tony Holmes To: freebsd-fs@FreeBSD.ORG Message-ID: <20030822130200.B82013@crosswinds.net> References: <20030822101702.A73928@crosswinds.net> <20030822164603.GB45178@cnd.mcgill.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20030822164603.GB45178@cnd.mcgill.ca>; from mat@cnd.mcgill.ca on Fri, Aug 22, 2003 at 12:46:03PM -0400 Subject: Re: RAID 1+0 X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 22 Aug 2003 17:02:02 -0000 On +Aug 22, Mathew Kanner wrote: > > Hello Tony, > I've just recently trashed a vinum raid10 volume by loosing > two disks. So, yes it is possible in vinum, look for "RAID-10" in the > manual. That's what I would call RAID-0+1 (mirroring stripes). Ie. plex A = 1 + 2 striped plex B = 3 + 4 striped volume = A + B mirrored Dead Drive Chart - if these drives die, how is data? Drive 1 2 3 4 1 OKAY OKAY DEAD DEAD 2 OKAY OKAY DEAD DEAD 3 DEAD OKAY OKAY OKAY 4 DEAD DEAD OKAY OKAY ie. 50% of the cases you can recover (drive 1 and 1 dying is single drive) What I'm looking for is RAID-1+0 (striping mirros) Ie. plex A = 1 + 2 mirrored plex B = 3 + 4 mirrored volume = A + B striped Drive 1 2 3 4 1 OKAY DEAD OKAY OKAY 2 DEAD OKAY OKAY OKAY 3 OKAY OKAY OKAY DEAD 4 OKAY OKAY DEAD OKAY ie. 75% of the cases you can recover For the RAID 1+0 case you require both drives of the same mirror to die to lose your data. Given vinums configuration file, we'd need something like the following that is not supported (just to help you visualize). drive d1 device /dev/da1e drive d2 device /dev/da2e drive d3 device /dev/da3e drive d4 device /dev/da4e volume raid10 setupstate plex org striped 512k subplex org concat sd length 512m drive d1 subplex org concat sd length 512m drive d2 plex org striped 512k subplex org concat sd length 512m drive d3 subplex org concat sd length 512m drive d4 -- Tony Holmes Founder and Senior Systems Architect Crosswinds Internet Communications Inc.