From owner-freebsd-hackers@FreeBSD.ORG Sat May 30 19:18:44 2009 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 4B0C1106566C for ; Sat, 30 May 2009 19:18:44 +0000 (UTC) (envelope-from xorquewasp@googlemail.com) Received: from mail-ew0-f212.google.com (mail-ew0-f212.google.com [209.85.219.212]) by mx1.freebsd.org (Postfix) with ESMTP id C279B8FC17 for ; Sat, 30 May 2009 19:18:43 +0000 (UTC) (envelope-from xorquewasp@googlemail.com) Received: by ewy8 with SMTP id 8so3507066ewy.43 for ; Sat, 30 May 2009 12:18:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:received:received:received:date:from:to:cc :subject:message-id:references:mime-version:content-type :content-disposition:in-reply-to; bh=dsT/5L1b4qdG13A5JhkrKOVqSvadVkJdDU1s851u634=; b=MPKCG58HspUlOum+ScsdnFxQsDDEiuEvUTMoQlpJ2D3H4DekWIQUO//RkirFtlOFxk kgtoA6uiaAohQwQHTWSg72D5boZw3vFMhEBIyFC3Pw1RNrgmoFaJlSGVf+3iajl+YH6z TFmZwl18XiL+urUAYvnH7ZyAfXguECGNGQwdw= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to; b=rKZHQGAK8vH7kFDRgIhV8glnwjMNqn8pe+p0DmKH3z45aAMJkJ/WJpaKq69tWJ3wUN zX6q8Rz9Sy5cs42fzW8TYY4VkpoMKcuYSEaz/OGlZbxfXeoC6oop2LVqbk9aIEE/lM4N pE6YPOUaLlD0w8u8MHsYBYLk2Boge0JMdejuE= Received: by 10.210.17.2 with SMTP id 2mr4201403ebq.0.1243711122234; Sat, 30 May 2009 12:18:42 -0700 (PDT) Received: from logik.internal.network (81-86-41-187.dsl.pipex.com [81.86.41.187]) by mx.google.com with ESMTPS id 22sm4043167ewy.40.2009.05.30.12.18.41 (version=TLSv1/SSLv3 cipher=OTHER); Sat, 30 May 2009 12:18:41 -0700 (PDT) Received: by logik.internal.network (Postfix, from userid 11001) id 3EF4D5D59; Sat, 30 May 2009 19:18:40 +0000 (UTC) Date: Sat, 30 May 2009 20:18:40 +0100 From: xorquewasp@googlemail.com To: Mike Meyer Message-ID: <20090530191840.GA68514@logik.internal.network> References: <20090530175239.GA25604@logik.internal.network> <20090530144354.2255f722@bhuda.mired.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090530144354.2255f722@bhuda.mired.org> Cc: freebsd-hackers@freebsd.org Subject: Re: Request for opinions - gvinum or ccd? X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 30 May 2009 19:18:44 -0000 On 2009-05-30 14:43:54, Mike Meyer wrote: > On Sat, 30 May 2009 18:52:39 +0100 > xorquewasp@googlemail.com wrote: > > Simple question then as the handbook describes both ccd and gvinum - > > which should I pick? > > My first reaction was "neither", then I realized - you didn't say what > version of FreeBSD you're running. But if you're running a supported > version of FreeBSD, that doesn't change my answer. Sorry, yeah. FreeBSD 7.2-RELEASE on AMD64. > If you're running 5.3 or later, you probably want gstripe. If you're > running something older than that, then gvinum won't be available > either, so you'll need to use ccd. I always figured gvinum was a > transition tool to help move from vinum to geom, which is why it's > managed to get to the 7.0 release with some pretty painful bugs in it, > which don't show up in gstripe. That sounds like the kind of entertainment I don't particularly want! > The handbook clearly needs to be rewritten - ccd isn't supported > anymore, except via the geom ccd class. However, I think zfs is going > to change it all again, so such a rewrite wont' be useful for very > long. I don't think zfs supports a two-disk stripe, thought it does do > JBOD. > > If you're running a 7.X 64-bit system with a couple of GIG of ram, > expect it to be in service for years without having to reformat the > disks, and can afford another drive, I'd recommend going to raidz on a > three-drive system. That will give you close to the size/performance > of your RAID0 system, but let you lose a disk without losing data. The > best you can do with zfs on two disks is a mirror, which means write > throughput will suffer. Certainly a lot to think about. The system has 12gb currently, with room to upgrade. I currently have two 500gb drives and one 1tb drive. I wanted the setup to be essentially two drives striped, backed up onto one larger one nightly. I wanted the large backup drive to be as "isolated" as possible, eg, in the event of some catastrophic hardware failure, I can remove it and place it in another machine without a lot of stressful configuration to recover the data (not possible with a RAID configuration involving all three drives, as far as I'm aware). xw