From owner-freebsd-fs@freebsd.org Tue Jan 16 14:03:20 2018 Return-Path: <owner-freebsd-fs@freebsd.org> Delivered-To: freebsd-fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 2448BE7142F for <freebsd-fs@mailman.ysv.freebsd.org>; Tue, 16 Jan 2018 14:03:20 +0000 (UTC) (envelope-from kwiat@panic.pl) Received: from mail.panic.pl (mail.panic.pl [188.68.250.13]) by mx1.freebsd.org (Postfix) with ESMTP id DB07B7AD90 for <freebsd-fs@freebsd.org>; Tue, 16 Jan 2018 14:03:19 +0000 (UTC) (envelope-from kwiat@panic.pl) Received: from mail.panic.pl (localhost [127.0.0.1]) by mail.panic.pl (Postfix) with ESMTP id E171F42A9B for <freebsd-fs@freebsd.org>; Tue, 16 Jan 2018 14:57:39 +0100 (CET) X-Virus-Scanned: amavisd-new at panic.pl Received: from mail.panic.pl ([127.0.0.1]) by mail.panic.pl (mail.panic.pl [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ip2HNSIVWIpk for <freebsd-fs@freebsd.org>; Tue, 16 Jan 2018 14:57:39 +0100 (CET) Received: from [192.168.0.28] (188.146.35.168.nat.umts.dynamic.t-mobile.pl [188.146.35.168]) by mail.panic.pl (Postfix) with ESMTPSA id E07E142A98 for <freebsd-fs@freebsd.org>; Tue, 16 Jan 2018 14:57:38 +0100 (CET) Subject: Re: Academic exercise: trying to recover a corrupted pool To: freebsd-fs@freebsd.org References: <F6B823C4-313E-4AF2-B1F6-6AFE8E17458B@sarenet.es> From: Mateusz Kwiatkowski <kwiat@panic.pl> Message-ID: <19f67e4f-7df8-6184-e396-aa8cde44eb83@panic.pl> Date: Tue, 16 Jan 2018 14:57:38 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.2 MIME-Version: 1.0 In-Reply-To: <F6B823C4-313E-4AF2-B1F6-6AFE8E17458B@sarenet.es> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Filesystems <freebsd-fs.freebsd.org> List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-fs>, <mailto:freebsd-fs-request@freebsd.org?subject=unsubscribe> List-Archive: <http://lists.freebsd.org/pipermail/freebsd-fs/> List-Post: <mailto:freebsd-fs@freebsd.org> List-Help: <mailto:freebsd-fs-request@freebsd.org?subject=help> List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-fs>, <mailto:freebsd-fs-request@freebsd.org?subject=subscribe> X-List-Received-Date: Tue, 16 Jan 2018 14:03:20 -0000 On 01/08/2018 03:25 PM, Borja Marcos wrote: > > Hi, > > ONLY AS AN ACADEMIC EXERCISE, WARNING :) > > I have a broken ZFS pool and I’m wondering wether it should be readable. The pool was made with four > apparently troublesome OCZ SSD drives pulled from other systems. They are connected to a LSI2008 adapter. > > The pool was created as a raidz2, so it’s supposed to survive the loss of two drives. It has lost two of them > and I am unable to import it. > > I have lost no useful data, I was using it just for testing. Now it has become an interesting study subject though :) > > Any ideas? I have tried to recover even doing the “radical thing†(zdb -Z -AAA -e -p /dev poolname). No success. > > Again, I am just curious. > > > Thanks! Few years ago I made similar exercise with pool broken by some ZFS on Linux bug. After many unsuccessful attempts to import the pool I came up with an idea to read data without importing the pool. Here's the script: https://gitlab.com/kwiat/zfs-recovery The code is in no way effective nor beautiful, but I learned a lot about ZFS when I was working on it. :-) -- Regards, Mateusz Kwiatkowski