From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f169.google.com ([209.85.192.169]:33849 "EHLO mail-pd0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751461AbbEZWoD (ORCPT ); Tue, 26 May 2015 18:44:03 -0400 Received: by pdbki1 with SMTP id ki1so59101352pdb.1 for ; Tue, 26 May 2015 15:44:02 -0700 (PDT) Date: Tue, 26 May 2015 15:44:00 -0700 From: Omar Sandoval To: Felix Koop Cc: linux-btrfs Subject: Re: Help needed to recover a RAID5 btrfs Message-ID: <20150526224400.GA28433@mew.lv.cox.net> References: <508094243.133459.1432569980190.JavaMail.open-xchange@oxbsltgw09.schlund.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 In-Reply-To: <508094243.133459.1432569980190.JavaMail.open-xchange@oxbsltgw09.schlund.de> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Mon, May 25, 2015 at 06:06:20PM +0200, Felix Koop wrote: > Hello, > > I have a RAID5 filesystem where one disk has crashed. Now the filesystem is not > recognized any more. Any help available? > > Here is some info: > > root@server:~# uname -a > Linux server 4.0.0-1-amd64 #1 SMP Debian 4.0.2-1 (2015-05-11) x86_64 GNU/Linux > > root@server:~# btrfs --version > btrfs-progs v4.0 > > root@server:~# btrfs f sh /dev/Data1vg/afs0 > warning, device 3 is missing > warning devid 3 not found already > checksum verify failed on 1111813750784 found 18019A1D wanted FCE227AB > checksum verify failed on 1111813750784 found 18019A1D wanted FCE227AB > bytenr mismatch, want=1111813750784, have=65536 > Couldn't read tree root > Label: none uuid: 7d4b023a-a1ef-4991-b01d-31e7c4fdfbcf > Total devices 3 FS bytes used 213.96GiB > devid 2 size 150.00GiB used 108.53GiB path /dev/mapper/Data1vg-afs0 > devid 4 size 150.00GiB used 108.53GiB path /dev/mapper/Data3vg-afs0 > *** Some devices missing > > btrfs-progs v4.0 > > root@server:~# mount -o degraded -r /dev/Data1vg/afs0 /mnt > mount: wrong fs type, bad option, bad superblock on /dev/mapper/Data1vg-afs0, > missing codepage or helper program, or other error > > In some cases useful info is found in syslog – try > dmesg | tail or so. > > root@server:~# dmesg | tail > [104991.996065] BTRFS: open_ctree failed > [105527.836798] blk_update_request: I/O error, dev fd0, sector 0 > [105527.839477] floppy: error -5 while reading block 0 > [105555.615991] BTRFS info (device dm-52): allowing degraded mounts > [105555.616000] BTRFS info (device dm-52): disk space caching is enabled > [105555.665644] BTRFS: bdev (null) errs: wr 38, rd 0, flush 0, corrupt 0, gen 0 > [105556.213570] BTRFS (device dm-52): bad tree block start 14290338419558610620 > 1111828267008 > [105556.216649] BTRFS (device dm-52): bad tree block start 14290338419558610620 > 1111828267008 > [105556.219364] BTRFS: Failed to read block groups: -5 > [105556.236056] BTRFS: open_ctree failed > > > If more info is needed, just tell me what I should do. Thanks. > Just a heads up if you manage to mount it, device replace of a missing device on RAID5/6 will currently oops (see [1]). If you're feeling really adventurous, you could try my unreviewed patch series here [2], but that of course depends on the degraded mount succeeding. 1: https://bugzilla.kernel.org/show_bug.cgi?id=96141 2: http://thread.gmane.org/gmane.comp.file-systems.btrfs/45045 -- Omar