From owner-freebsd-stable@FreeBSD.ORG Mon Oct 20 17:19:29 2008 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2698A106567A for ; Mon, 20 Oct 2008 17:19:29 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from QMTA02.emeryville.ca.mail.comcast.net (qmta02.emeryville.ca.mail.comcast.net [76.96.30.24]) by mx1.freebsd.org (Postfix) with ESMTP id 03CEC8FC20 for ; Mon, 20 Oct 2008 17:19:28 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from OMTA04.emeryville.ca.mail.comcast.net ([76.96.30.35]) by QMTA02.emeryville.ca.mail.comcast.net with comcast id V5131a00w0lTkoCA25KU28; Mon, 20 Oct 2008 17:19:28 +0000 Received: from koitsu.dyndns.org ([69.181.141.110]) by OMTA04.emeryville.ca.mail.comcast.net with comcast id V5KT1a00n2P6wsM8Q5KUTo; Mon, 20 Oct 2008 17:19:28 +0000 X-Authority-Analysis: v=1.0 c=1 a=QycZ5dHgAAAA:8 a=RHSQrUapfjfyGxU2_IMA:9 a=DnCppsHdm3qqYWit-jV4gjLFsEcA:4 a=EoioJ0NPDVgA:10 a=LY0hPdMaydYA:10 Received: by icarus.home.lan (Postfix, from userid 1000) id CBE8FC9437; Mon, 20 Oct 2008 10:19:27 -0700 (PDT) Date: Mon, 20 Oct 2008 10:19:27 -0700 From: Jeremy Chadwick To: Chuck Swiger Message-ID: <20081020171927.GB8551@icarus.home.lan> References: <200810171530.45570.joao@matik.com.br> <200810200837.40451.joao@matik.com.br> <20081020132208.GA3847@icarus.home.lan> <98238FC8-0FC4-4410-829F-EF2EA16A57B8@mac.com> <20081020164831.GA8016@icarus.home.lan> <45836B9A-CB6E-4B95-911E-0023230B8F82@mac.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <45836B9A-CB6E-4B95-911E-0023230B8F82@mac.com> User-Agent: Mutt/1.5.18 (2008-05-17) Cc: freebsd-stable@freebsd.org, JoaoBR Subject: Re: constant zfs data corruption X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 20 Oct 2008 17:19:29 -0000 On Mon, Oct 20, 2008 at 10:03:14AM -0700, Chuck Swiger wrote: > On Oct 20, 2008, at 9:48 AM, Jeremy Chadwick wrote: >> Hm... I thought we determined earlier in this thread that the OP is >> not >> getting the benefits of ZFS checksums because he's not using raidz >> (only >> a single disk with a single pool)? > > He's not getting working filesystem redundancy with the existing config > and is vulnerable to losing data from a single drive failure, agreed. > But the ZFS checksum mechanism should still be working to detect data > corruption, even though ZFS cannot recover the corrupted data the way it > otherwise would if redundancy was available. Ahh, I see. So to paraphrase, ZFS can detect checksum errors (data corruption) using any pool type (single disk, mirror, raidz, whatever), but can only *repair* the error when using a mirror or raidz. -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |