From owner-freebsd-stable@FreeBSD.ORG Mon Oct 20 18:37:24 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 7B6AF10656D2; Mon, 20 Oct 2008 18:37:24 +0000 (UTC) (envelope-from delphij@delphij.net) Received: from tarsier.delphij.net (delphij-pt.tunnel.tserv2.fmt.ipv6.he.net [IPv6:2001:470:1f03:2c9::2]) by mx1.freebsd.org (Postfix) with ESMTP id 1D1108FC24; Mon, 20 Oct 2008 18:37:24 +0000 (UTC) (envelope-from delphij@delphij.net) Received: from tarsier.geekcn.org (tarsier.geekcn.org [211.166.10.233]) (using TLSv1 with cipher ADH-CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by tarsier.delphij.net (Postfix) with ESMTPS id C991328454; Tue, 21 Oct 2008 02:37:22 +0800 (CST) Received: from localhost (tarsier.geekcn.org [211.166.10.233]) by tarsier.geekcn.org (Postfix) with ESMTP id 5A4B7EB33A5; Tue, 21 Oct 2008 02:37:22 +0800 (CST) X-Virus-Scanned: amavisd-new at geekcn.org Received: from tarsier.geekcn.org ([211.166.10.233]) by localhost (mail.geekcn.org [211.166.10.233]) (amavisd-new, port 10024) with ESMTP id tnaWoUhDyMJY; Tue, 21 Oct 2008 02:37:17 +0800 (CST) Received: from charlie.delphij.net (adsl-76-237-33-62.dsl.pltn13.sbcglobal.net [76.237.33.62]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by tarsier.geekcn.org (Postfix) with ESMTPSA id 9A0CAEB1A31; Tue, 21 Oct 2008 02:37:15 +0800 (CST) DomainKey-Signature: a=rsa-sha1; s=default; d=delphij.net; c=nofws; q=dns; h=message-id:date:from:reply-to:organization:user-agent: mime-version:to:cc:subject:references:in-reply-to: x-enigmail-version:openpgp:content-type:content-transfer-encoding; b=gxKyExaMrEbnSmHj1o+A6x0eld1JH6pNa632tSswcAiDf3I3R1PmKAozGHStURpn1 MySWnq/8Q1l3s8DAcTh7g== Message-ID: <48FCCFD9.70807@delphij.net> Date: Mon, 20 Oct 2008 11:37:13 -0700 From: Xin LI Organization: The FreeBSD Project User-Agent: Thunderbird 2.0.0.17 (X11/20080928) MIME-Version: 1.0 To: Jeremy Chadwick 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> <20081020171927.GB8551@icarus.home.lan> In-Reply-To: <20081020171927.GB8551@icarus.home.lan> X-Enigmail-Version: 0.95.7 OpenPGP: id=18EDEBA0; url=http://www.delphij.net/delphij.asc Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit 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 Reply-To: d@delphij.net 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 18:37:24 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Jeremy Chadwick wrote: [snip] > 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. Also when copies >= 2. This is very useful for e.g. laptops. I have set copies=2 for all zfs file systems (not on the whole pool) storing important personal data (/home, /usr/src), and after 3 times (!) of hard drive bad sector incidents (all replaced after recoverdisk) within 6 months, I was very lucky not to use the last resort by restoring data from my monthly DVD-R backup. Cheers, - -- Xin LI http://www.delphij.net/ FreeBSD - The Power to Serve! -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (FreeBSD) iEYEARECAAYFAkj8z9kACgkQi+vbBBjt66CdBwCeO+ADiDOzAjcG4w16AJkOaUo4 xskAnRPVynvvVWWfMm2zd/T2KGB4/s2U =M2aF -----END PGP SIGNATURE-----