From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from magic.merlins.org ([209.81.13.136]:49671 "EHLO mail1.merlins.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753299AbcJ3Sr4 (ORCPT ); Sun, 30 Oct 2016 14:47:56 -0400 Received: from merlin by mail1.merlins.org with local (Exim 4.87 #1) id 1c0uwI-00013I-3K by authid for ; Sun, 30 Oct 2016 11:34:38 -0700 Date: Sun, 30 Oct 2016 11:34:38 -0700 From: Marc MERLIN To: linux-btrfs@vger.kernel.org Subject: btrfs check --repair: ERROR: cannot read chunk root Message-ID: <20161030183437.GA3287@merlins.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-btrfs-owner@vger.kernel.org List-ID: I have a filesystem on top of md raid5 that got a few problems due to the underlying block layer (bad data cable). The filesystem mounts fine, but had a few issues Scrub runs (I didn't let it finish, it takes a _long_ time) But check --repair won't even run at all: myth:~# btrfs --version btrfs-progs v4.7.3 myth:~# uname -r 4.8.5-ia32-20161028 myth:~# btrfs check -p --repair /dev/mapper/crypt_bcache0 2>&1 | tee /var/spool/repair bytenr mismatch, want=13835462344704, have=0 ERROR: cannot read chunk root Couldn't open file system enabling repair mode myth:~# myth:~# btrfs rescue super-recover -v /dev//mapper/crypt_bcache0 All Devices: Device: id = 1, name = /dev//mapper/crypt_bcache0 Before Recovering: [All good supers]: device name = /dev//mapper/crypt_bcache0 superblock bytenr = 65536 device name = /dev//mapper/crypt_bcache0 superblock bytenr = 67108864 device name = /dev//mapper/crypt_bcache0 superblock bytenr = 274877906944 [All bad supers]: All supers are valid, no need to recover I don't care about the data, it's a backup array, but I'd still like to know if I can recover from this state and do a repair to see how much data got damaged Thanks, Marc -- "A mouse is a device used to point at the xterm you want to type in" - A.S.R. Microsoft is to operating systems .... .... what McDonalds is to gourmet cooking Home page: http://marc.merlins.org/