Return-Path: Received: from dnvrco-outbound-snat.email.rr.com ([107.14.73.230]:38292 "EHLO dnvrco-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750714AbcKQWIX (ORCPT ); Thu, 17 Nov 2016 17:08:23 -0500 Received: from localhost (localhost [127.0.0.1]) by smtp.aresgate.net (smtpd) with ESMTP id 91EF493CAD8 for ; Thu, 17 Nov 2016 14:01:16 -0800 (PST) Received: from smtp.aresgate.net ([127.0.0.1]) by localhost (smtp.aresgate.net [127.0.0.1]) (amavisd-new, port 10024) with LMTP id LAlOj-Z_PsKZ for ; Thu, 17 Nov 2016 14:01:15 -0800 (PST) Received: from gypsyops.denof.sin (cpe-76-172-86-115.socal.res.rr.com [76.172.86.115]) by smtp.aresgate.net (smtpd) with ESMTPSA id 6C53E93CAD0 for ; Thu, 17 Nov 2016 14:01:15 -0800 (PST) Date: Thu, 17 Nov 2016 14:01:11 -0800 From: Vladi Gergov To: linux-btrfs@vger.kernel.org Subject: btrfs raid1 degraded needs chunk root rebuild Message-ID: <20161117220111.GA13765@gypsyops.denof.sin> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-btrfs-owner@vger.kernel.org List-ID: Any ideas if currently I can still recover data from this volume? I have tried the new btrfs tools with btrfs rescue chunk-recover without much success. Any ideas if i can recover any of the data? ----- Forwarded message from Chris Mason ----- From: Chris Mason Subject: Re: btrfs raid1 degraded does not mount or fsck To: Vladi Gergov Cc: linux-btrfs Date: Tue, 16 Nov 2010 16:50:58 -0500 User-Agent: Sup/git Excerpts from Vladi Gergov's message of 2010-10-29 16:53:42 -0400: > >>> gypsyops @ /mnt > sudo mount -o degraded /dev/sdc das3/ > Password: > mount: wrong fs type, bad option, bad superblock on /dev/sdc, > missing codepage or helper program, or other error > In some cases useful info is found in syslog - try > dmesg | tail or so > > [ 684.577540] device label das4 devid 2 transid 107954 /dev/sdc > [ 684.595150] btrfs: allowing degraded mounts > [ 684.595594] btrfs: failed to read chunk root on sdb > [ 684.604110] btrfs: open_ctree failed > > >>> gypsyops @ /mnt > sudo btrfsck /dev/sdc > btrfsck: volumes.c:1367: btrfs_read_sys_array: Assertion `!(ret)' failed. Ok, I dug through this and found the bug responsible for your unmountable FS. When we're mounted in degraded mode, and we don't have enough drives available to do raid1,10, we're can use the wrong raid level for new allocations. I'm fixing the kernel side so this doesn't happen anymore, but I'll need to rebuild the chunk tree (and probably a few others) off your good disk to fix things. I've got it reproduced here though, so I'll make an fsck that can scan for the correct trees and fix it for you. Since you're basically going to be my first external fsck customer, is there anyway you can do a raw device based backup of the blocks? This way if I do mess things up we can repeat the experiment. -chris !DSPAM:4ce2fd55191821234852255! ----- End forwarded message ----- -- ,-| Vladi `-| Gergov