From owner-freebsd-fs@FreeBSD.ORG Wed Jul 13 16:38:10 2011 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 61DFB1065670 for ; Wed, 13 Jul 2011 16:38:10 +0000 (UTC) (envelope-from artemb@gmail.com) Received: from mail-wy0-f182.google.com (mail-wy0-f182.google.com [74.125.82.182]) by mx1.freebsd.org (Postfix) with ESMTP id E963C8FC1E for ; Wed, 13 Jul 2011 16:38:09 +0000 (UTC) Received: by wyg24 with SMTP id 24so359908wyg.13 for ; Wed, 13 Jul 2011 09:38:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=lTrgxdvoFMC5bA2XhyDc5j2Kxt3B0dg06qul0/nrd0c=; b=KrFack8VzVGFObJXYREm/CH7LNdpBPFxHPmKp9lOdQmnZWQraMy7u2ttOwopxfLvwc KzZcYgcwlqWVraBHsxw6VZx7unwLmNn2eCoD5NMZ7eu8aTmyFyiL5DcLOEElpcj3XinP C3644eTAnq5KOQZAwUgXfrmhcXCC3/AmEzfdc= MIME-Version: 1.0 Received: by 10.216.61.198 with SMTP id w48mr1121438wec.40.1310575087229; Wed, 13 Jul 2011 09:38:07 -0700 (PDT) Sender: artemb@gmail.com Received: by 10.216.46.18 with HTTP; Wed, 13 Jul 2011 09:38:07 -0700 (PDT) In-Reply-To: <94D74687DE95420486730136248EEB77@multiplay.co.uk> References: <69E82BC1AF1E4F50B37119C4E614B190@multiplay.co.uk> <94D74687DE95420486730136248EEB77@multiplay.co.uk> Date: Wed, 13 Jul 2011 09:38:07 -0700 X-Google-Sender-Auth: fzdyRyr5RzUBR6V48Zuj-of9NXs Message-ID: From: Artem Belevich To: Steven Hartland Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: freebsd-fs@freebsd.org Subject: Re: Forcing a full file read in ZFS even when checksum error encountered X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 13 Jul 2011 16:38:10 -0000 On Wed, Jul 13, 2011 at 3:01 AM, Steven Hartland wrote: > ----- Original Message ----- From: "Artem Belevich" >> >> Maybe. See here: >> http://blogs.oracle.com/relling/entry/holy_smokes_a_holey_file >> >> Using that method you still would not get the bad block, but you may >> be able to recover data beyond it. >> >> If you really want to get access to the data that ZFS considers to be >> corrupted, you need to get close and personal with zdb. >> This blog post may be a good starting point: >> http://cuddletech.com/blog/?p=3D407 > > Perfect, thanks Artem. > > For the record using the following zdb commands I've managed to get the > file data off the pool. > > 1. zdb -dddd / (find the objectid by searching for the > filename) If I understand it correctly, opjectid is used as inode number. "ls -i" would let you find it a bit faster. --Artem > 2. zdb -ddddd / (find the indirect blocks, the > third block of hex) > 3. zdb -R : 2>/tmp/filedata > > e.g. > zdb -dddd tank/usr > zdb -ddddd tank/usr 1243 > zdb -R tank:0:22df120000:18000:r 2>corrupt.jpg > > =A0 Regards > =A0 Steve > > > > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > This e.mail is private and confidential between Multiplay (UK) Ltd. and t= he > person or entity to whom it is addressed. In the event of misdirection, t= he > recipient is prohibited from using, copying, printing or otherwise > disseminating it or any information contained in it. > In the event of misdirection, illegible or incomplete transmission please > telephone +44 845 868 1337 > or return the E.mail to postmaster@multiplay.co.uk. > >