From owner-freebsd-questions@FreeBSD.ORG Fri Jan 12 22:18:21 2007 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 09F9A16A407 for ; Fri, 12 Jan 2007 22:18:21 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from mail-out3.apple.com (mail-out3.apple.com [17.254.13.22]) by mx1.freebsd.org (Postfix) with ESMTP id E69A713C45A for ; Fri, 12 Jan 2007 22:18:20 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from relay5.apple.com (relay5.apple.com [17.128.113.35]) by mail-out3.apple.com (8.13.8/8.13.8) with ESMTP id l0CMIK4E010394; Fri, 12 Jan 2007 14:18:20 -0800 (PST) Received: from relay5.apple.com (unknown [127.0.0.1]) by relay5.apple.com (Symantec Mail Security) with ESMTP id A05FD29C003; Fri, 12 Jan 2007 14:18:20 -0800 (PST) X-AuditID: 11807123-a2358bb0000039f2-ea-45a8092cb85c Received: from [17.214.13.96] (unknown [17.214.13.96]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by relay5.apple.com (Apple SCV relay) with ESMTP id 93B2130400B; Fri, 12 Jan 2007 14:18:20 -0800 (PST) In-Reply-To: <45A7FB43.40208@u.washington.edu> References: <45A7FB43.40208@u.washington.edu> Mime-Version: 1.0 (Apple Message framework v752.2) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: Content-Transfer-Encoding: 7bit From: Chuck Swiger Date: Fri, 12 Jan 2007 14:18:19 -0800 To: Garrett Cooper X-Mailer: Apple Mail (2.752.2) X-Brightmail-Tracker: AAAAAA== Cc: freebsd-questions@freebsd.org Subject: Re: Recovering select files from a failing hard disk X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 12 Jan 2007 22:18:21 -0000 On Jan 12, 2007, at 1:18 PM, Garrett Cooper wrote: > 1. Can I bypass mounting or reading certain sections of the > filesystem? Sure, if you boot off some other device or a CD-ROM. > 2. Can I force part of a drive to be remapped to other sectors? Yes, but it is likely that modern drives will have automatically reassigned failing sectors already, until it ran out of spare sectors. If you've got an older SCSI system, you might try running your adaptor's BIOS utility and having it do a device verify; that will encourage the drive to remap problematic sectors. > 3. Is there a backup superblock on the disk and what would it be? I > know > this feature exists on some filesystems, but I'm not sure if UFS is > one > of those filesystems. There are many backup superblocks kept on the disk; "fsck -b 32" will try using the first alternate, but there will be others scattered about. You can run "dumpfs" to locate more, I believe. > The reason for these questions is that I believe that the > portion of my failing hard disk is involved with the statistics > portion > for the data slice or a series of directories. So, I want to grab the > files off my disk and just dump the thing asap. OK. You might try doing a block-copy with dd to a new drive, and then trying to fsck or repair the data on that copy rather than trying to fix the filesystem on the failing drive... -- -Chuck