From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2DBD1C65C30 for ; Sun, 7 Oct 2018 06:48:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CC34C2088F for ; Sun, 7 Oct 2018 06:48:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="HobW20NI" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CC34C2088F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-btrfs-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726396AbeJGNyQ (ORCPT ); Sun, 7 Oct 2018 09:54:16 -0400 Received: from mail-qt1-f173.google.com ([209.85.160.173]:46752 "EHLO mail-qt1-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726308AbeJGNyP (ORCPT ); Sun, 7 Oct 2018 09:54:15 -0400 Received: by mail-qt1-f173.google.com with SMTP id d8-v6so17958672qtk.13 for ; Sat, 06 Oct 2018 23:47:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=f1MCDfKbYaY6Y/wXTYJtLQ5utrinQNFQ19KugUYy8mI=; b=HobW20NIS0AYriZcNcKf7GdEzNTudF+9QlTVvxcCWs0dFz9lAGFgL3Ky1V3S3JBvN1 MJdKN+esz2AKrMtk0JKmSpbPAzn3Mf747SkHtLT1rsiMCjGqtYcdtznC/yRjr16BfzFb P2J8Ujyna4W6+i/vuMFl67I91DY4fCH0QlPO0D4xOoPELoVZcj6BikXcAZeqVqX9zyIp 4jZVbfrqcV5xa1mbQELFx2/xnKosLj3JqpWc0IA+su3bvVOnPsquj3pLV3S2htr9iMLs vUsfPFu+8ffZtZ2+3NBPQrgB1YW9dVsBjUw9vHglyQd2y0bPYOIGptwvTeMOBRc13DQq gJjQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=f1MCDfKbYaY6Y/wXTYJtLQ5utrinQNFQ19KugUYy8mI=; b=r5PpC9X43/6Qph/hO6pv4TbD5mbnyhJZ7kWkex8Hyz7KN3RrySJC/QG08sFEUZDUTX Pszb2U1RXV8+hthyakclrhrLeg7m3cdMRnko2fHOJAkcdv2tWc/SGrWWhvj62Qszrslm vyU5tuPlCdNKAw3PRa4Iq7G0evHgW3xw3b6BW/hBmye5cUmlDM0QG14L078r3ngascnM Ev2S8kQsy2MT0IXxMFb1MHKTodGGx3K73wzxpa7mwrJ2FP6GDGTsSU3O0eivmqGk+4YH NQnMdJT33XNmVHm6QBBKCtpM63GJBQiyouQdE749IIrv50RMPHmpl8P0yX6x5AcChevb vFFw== X-Gm-Message-State: ABuFfojol5EPXYeGiwsYVCcA516y7yx5zfF4N/yzdvdukYA6YEOHIj2G TADGWO+bDztg7RrRhqk1j6O4NheyRxNX682dbxE= X-Google-Smtp-Source: ACcGV63jy+OsepfT3ixPJs6NQDDJDXGFJoSMJwLsQqjguM+svSexE4zyo6i/a+nJnUXrGfNfOCoh2yczByScHDQTHAM= X-Received: by 2002:a0c:a8c3:: with SMTP id h3-v6mr4089455qvc.217.1538894878809; Sat, 06 Oct 2018 23:47:58 -0700 (PDT) MIME-Version: 1.0 References: <54132790-3f56-ef0f-d818-4f62f0b0a608@gmx.com> <64cd61fe-5e78-6201-f4b2-e88efba139bc@gmx.com> In-Reply-To: <64cd61fe-5e78-6201-f4b2-e88efba139bc@gmx.com> From: evan d Date: Sun, 7 Oct 2018 08:47:47 +0200 Message-ID: Subject: Re: Two partitionless BTRFS drives no longer seen as containing BTRFS filesystem To: quwenruo.btrfs@gmx.com Cc: linux-btrfs@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org > None of your super blocks has correct magic. I take it this applies to both drives? > This means either your whole disk get corrupted, or something introduced > some offset. > > Please try the following commands to dump more data around super blocks, > so we could be able to find the possible offset: > > # dd if=/dev/sdb of=possible_sb_range.raw bs=1M count=128 > # grep -obUaP "\x5F\x42\x48\x52\x66\x53\x5F\x4D" possible_sb_range. > > For a valid btrfs without any offset, the result should look like: > 65600:_BHRfS_M > 67108928:_BHRfS_M # dd if=/dev/sdc of=possible_sb_range.sdc.raw bs=1M count=128 128+0 records in 128+0 records out 134217728 bytes (134 MB, 128 MiB) copied, 0.737479 s, 182 MB/s # dd if=/dev/sdb of=possible_sb_range.sdb.raw bs=1M count=128 128+0 records in 128+0 records out 134217728 bytes (134 MB, 128 MiB) copied, 0.726327 s, 185 MB/s # grep -obUaP "\x5F\x42\x48\x52\x66\x53\x5F\x4D" possible_sb_range.sdb.raw # grep -obUaP "\x5F\x42\x48\x52\x66\x53\x5F\x4D" possible_sb_range.sdc.raw Both return nothing. Both drives pass S.M.A.R.T. testing so I'd have to think the corruption stems from some kind of offset rather than random corruption. They may have accidentally been inserted into a Windows machine (but not partitioned or formatted). Could this be a likely cause?