From owner-freebsd-hackers@FreeBSD.ORG Mon Jun 1 02:44:28 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 CD036106566C for ; Mon, 1 Jun 2009 02:44:28 +0000 (UTC) (envelope-from fjwcash@gmail.com) Received: from yx-out-2324.google.com (yx-out-2324.google.com [74.125.44.29]) by mx1.freebsd.org (Postfix) with ESMTP id 7FC538FC0A for ; Mon, 1 Jun 2009 02:44:28 +0000 (UTC) (envelope-from fjwcash@gmail.com) Received: by yx-out-2324.google.com with SMTP id 8so3789863yxb.13 for ; Sun, 31 May 2009 19:44:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type :content-transfer-encoding; bh=vH1dZvtqZZNDXWKCKLMfT/dspX2heCzPWrEbvGutqOo=; b=wThNGNjbykUIxO8yMa53H/CNpXSgRpeNoJjPAkPvWmJh2SqBmp89HxU8ukiALA72J8 PYjik3xNW5zNsP6OcOOW57s5IdMvwWBsnPuwopxcX8MGK8Vdyx3RjfaGEdqsVHtiq44p 32rUfGFzptCKd3CamApXF5rRzFbiacVcmMRnw= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; b=tPVkTFvzHYkUi+ve1UvFlXXqFWTJwXpwBik+5oue4gVx8wFW7N+jsJ3w/TIAYKde44 I4Y/2k83rd0dr5ic4fgRxuVJG5bgBP3lllsZEgZmdzbB3s/5InEX4oM3mB0ijncFeyto 3U0Bup9U3/CxmREFRFeHu/sXcFniq9MTE1leI= MIME-Version: 1.0 Received: by 10.151.72.2 with SMTP id z2mr10677028ybk.15.1243822446881; Sun, 31 May 2009 19:14:06 -0700 (PDT) In-Reply-To: <20090531235943.GA77374@logik.internal.network> References: <20090530175239.GA25604@logik.internal.network> <20090530144354.2255f722@bhuda.mired.org> <20090530191840.GA68514@logik.internal.network> <20090530162744.5d77e9d1@bhuda.mired.org> <20090531201445.GA82420@logik.internal.network> <0229B3BF1BE94C82AA11FD06CBE0BDEF@uk.tiscali.intl> <20090531235943.GA77374@logik.internal.network> Date: Sun, 31 May 2009 19:14:06 -0700 Message-ID: From: Freddie Cash To: freebsd-hackers@freebsd.org Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable 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: Mon, 01 Jun 2009 02:44:29 -0000 On Sun, May 31, 2009 at 4:59 PM, wrote: > There is one last thing I'd like clarified. From the zpool > manpage: > > =C2=A0In order =C2=A0to take advantage of these features, a pool must mak= e use of > =C2=A0some form of redundancy, using either mirrored or raidz =C2=A0group= s. =C2=A0While > =C2=A0ZFS =C2=A0supports running in a non-redundant configuration, where = each root > =C2=A0vdev is simply a disk or file, this is strongly discouraged. =C2=A0= A =C2=A0single > =C2=A0case of bit corruption can render some or all of your data unavaila= ble. > > Is this supposed to mean: > > =C2=A0"ZFS is more fragile than most. If you don't use redundancy, one > =C2=A0 case of bit corruption will destroy the filesystem" > > Or: > > =C2=A0"Hard disks explode often. Use redundancy." Unless you specify mirror or raidz on the create/add line, zfs (in essence) creates a RAID0 stripe of all the vdevs. Hence, if a single drive dies, the whole thing dies. Just like in a normal hardware/software RAID0 array. Nothing special or new here. Just like "normal" RAID, unless you add redundancy (RAID1/5/6) to a stripe set, losing a single disk means losing the whole array. --=20 Freddie Cash fjwcash@gmail.com