From owner-freebsd-stable@FreeBSD.ORG Tue Aug 21 11:02:11 2007 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 CFC9E16A417 for ; Tue, 21 Aug 2007 11:02:11 +0000 (UTC) (envelope-from davids@webmaster.com) Received: from mail1.webmaster.com (mail1.webmaster.com [216.152.64.169]) by mx1.freebsd.org (Postfix) with ESMTP id B87B013C45B for ; Tue, 21 Aug 2007 11:02:11 +0000 (UTC) (envelope-from davids@webmaster.com) Received: from however by webmaster.com (MDaemon.PRO.v8.1.3.R) with ESMTP id md50001647420.msg for ; Tue, 21 Aug 2007 04:02:12 -0700 From: "David Schwartz" To: Date: Tue, 21 Aug 2007 04:01:40 -0700 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.6604 (9.0.2911.0) Importance: Normal In-Reply-To: <4F9C9299A10AE74E89EA580D14AA10A61A17E0@royal64.emp.zapto.org> X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 X-Authenticated-Sender: joelkatz@webmaster.com X-Spam-Processed: mail1.webmaster.com, Tue, 21 Aug 2007 04:02:12 -0700 (not processed: message from trusted or authenticated source) X-MDRemoteIP: 206.171.168.138 X-Return-Path: davids@webmaster.com X-MDaemon-Deliver-To: freebsd-stable@freebsd.org X-MDAV-Processed: mail1.webmaster.com, Tue, 21 Aug 2007 04:02:13 -0700 Subject: RE: A little story of failed raid5 (3ware 8000 series) X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: davids@webmaster.com List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 21 Aug 2007 11:02:11 -0000 > While we are on the subject: > > What is the practical difference between VERIFY and REBUILD with regards > to a RAID-5 array? Verify should at a minimum read all the data. Ideally, it would read the checksum blocks too to make sure they are still valid, but it might not. Rebuild should read all the data and write out new checksum blocks. It might also validate that it can read back the checksum. > My Highpoint RocketRAID 2320 and 2340 cards can be scheduled to perform > either verify or rebuild. I currently have them set to verify the arrays > weekly. Is that reasonably often? Do I want to rebuild regularly also > (or instead of verify)? It really depends what these functions actually do. Ideally, verify would read the data and the checksum and so would ensure that all data can be read, even if one drive fails. If so, that would really be all you need to do periodically. DS