From owner-freebsd-questions@FreeBSD.ORG Tue Jan 5 19:28:59 2010 Return-Path: Delivered-To: questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 78D301065670 for ; Tue, 5 Jan 2010 19:28:59 +0000 (UTC) (envelope-from fbsdlists@gmail.com) Received: from mail-pw0-f44.google.com (mail-pw0-f44.google.com [209.85.160.44]) by mx1.freebsd.org (Postfix) with ESMTP id 50CAA8FC13 for ; Tue, 5 Jan 2010 19:28:59 +0000 (UTC) Received: by pwi15 with SMTP id 15so11363660pwi.3 for ; Tue, 05 Jan 2010 11:28:57 -0800 (PST) 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:cc:content-type; bh=g7VMy7NAe5eU6aKL3F2CgcFlAcryJIWNg3FiIhS+aDc=; b=wObR77z4PiBczcxNHKINDmolyR09nWxIoI7hgTSiB5NBlTW6HHacJfJu0jfY3E04A0 K8WUOtDlymSjT8IF4co8l/eT2N+sPvntPzY7zphC659C2pqJNtjaa057/dkeBYdNsbV5 1qQl2qTuPj3qcJlK0XaIMV4vYFO2+bRAMjmOM= 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 :cc:content-type; b=ezLJWVqIOqUdTDWoI6Rx/7wh/u5l8pqmf8bh77bSGoBHPxTTBgtYUTBIiPeLJg+Du0 wXZZzWrlidX5nebS/jBHvMKlfei+K8lyQdHv1dmc7vprOE7k7XAY1DpeirQlZeOiAb9s cd3fnUU4jRhLxeboHpPoML5mbhRHqJ5r0fyfE= MIME-Version: 1.0 Received: by 10.142.61.25 with SMTP id j25mr7565663wfa.320.1262719737211; Tue, 05 Jan 2010 11:28:57 -0800 (PST) In-Reply-To: <20100105191645.GA1782@darklight.org.ru> References: <4B434D52.3030301@kukulies.org> <20100105191645.GA1782@darklight.org.ru> Date: Tue, 5 Jan 2010 14:28:57 -0500 Message-ID: <54db43991001051128s3521b7b5hdf70f60672437533@mail.gmail.com> From: Bob Johnson To: FreeBSD Questions Content-Type: text/plain; charset=ISO-8859-1 Cc: Christoph Kukulies Subject: Re: copying a disk with ignoring errors 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: Tue, 05 Jan 2010 19:28:59 -0000 On 1/5/10, Yuri Pankov wrote: > On Tue, Jan 05, 2010 at 03:31:46PM +0100, Christoph Kukulies wrote: >> I recall a case when I had a hard disk that had got bad sectors and >> it wasn't accessible through normal mounting anymore. >> Then a tool came into the game that - I believe - Poul Henning had >> recommended or written for this purpose. >> >> It copies a disk sector by sector to a file (kind of dd), but >> ignores errors, it just skips sectors it couldn't read (after a >> couple >> of retries). The result was, that one had a - albeit - worm-eaten - >> image of the disk allowing to access the filesystem >> and getting to the important files with a little luck these not >> being amongst the corrupted data. >> >> Anyone knowing what this little tool was named? Something like >> diskcopy, devcopy, I forgot. >> >> -- >> Christoph > > dd conv=noerror? I think you need sync also. E.g. dd if=/dev/ad3 of=disk.img bs=512 conv=sync,noerror will replace the unreadable blocks with blocks of NULs. -- -- Bob Johnson