From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f53.google.com ([74.125.82.53]:36178 "EHLO mail-wg0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751171AbbEJOiF (ORCPT ); Sun, 10 May 2015 10:38:05 -0400 Received: by wgiu9 with SMTP id u9so107968683wgi.3 for ; Sun, 10 May 2015 07:38:03 -0700 (PDT) Received: from [10.0.2.15] (p4FCB5E8C.dip0.t-ipconnect.de. [79.203.94.140]) by mx.google.com with ESMTPSA id dg8sm18299778wjc.9.2015.05.10.07.38.01 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 10 May 2015 07:38:02 -0700 (PDT) From: Philip Seeger Message-ID: <554F6D43.2060806@googlemail.com> Date: Sun, 10 May 2015 16:37:55 +0200 MIME-Version: 1.0 To: linux-btrfs@vger.kernel.org Subject: Got 10 csum errors according to dmesg but 0 errors according to dev stats Content-Type: text/plain; charset=utf-8; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: I have installed a new virtual machine (VirtualBox) with Arch on btrfs (just a root fs and swap partition, no other partitions). I suddenly noticed 10 checksum errors in the kernel log: $ dmesg | grep csum [ 736.283506] BTRFS warning (device sda1): csum failed ino 1704363 off 761856 csum 1145980813 expected csum 2566472073 [ 736.283605] BTRFS warning (device sda1): csum failed ino 1704363 off 1146880 csum 1961240434 expected csum 2566472073 [ 745.583064] BTRFS warning (device sda1): csum failed ino 1704346 off 393216 csum 4035064017 expected csum 2566472073 [ 752.324899] BTRFS warning (device sda1): csum failed ino 1705927 off 2125824 csum 3638986839 expected csum 2566472073 [ 752.333115] BTRFS warning (device sda1): csum failed ino 1705927 off 2588672 csum 176788087 expected csum 2566472073 [ 752.333303] BTRFS warning (device sda1): csum failed ino 1705927 off 3276800 csum 1891435134 expected csum 2566472073 [ 752.333397] BTRFS warning (device sda1): csum failed ino 1705927 off 3964928 csum 3304112727 expected csum 2566472073 [ 2761.889460] BTRFS warning (device sda1): csum failed ino 1705927 off 2125824 csum 3638986839 expected csum 2566472073 [ 9054.226022] BTRFS warning (device sda1): csum failed ino 1704363 off 761856 csum 1145980813 expected csum 2566472073 [ 9054.226106] BTRFS warning (device sda1): csum failed ino 1704363 off 1146880 csum 1961240434 expected csum 2566472073 This is a new vm, it hasn't crashed (which might have caused filesystem corruption). The virtual disk is on a RAID storage on the host, which is healthy. All corrupted files are Firefox data files: $ dmesg | grep csum | grep -Eo 'csum failed ino [0-9]* ' | awk '{print $4}' | xargs -I{} find -inum {} ./.mozilla/firefox/nfh217zw.default/cookies.sqlite ./.mozilla/firefox/nfh217zw.default/cookies.sqlite ./.mozilla/firefox/nfh217zw.default/webappsstore.sqlite ./.mozilla/firefox/nfh217zw.default/places.sqlite ./.mozilla/firefox/nfh217zw.default/places.sqlite ./.mozilla/firefox/nfh217zw.default/places.sqlite ./.mozilla/firefox/nfh217zw.default/places.sqlite ./.mozilla/firefox/nfh217zw.default/places.sqlite ./.mozilla/firefox/nfh217zw.default/cookies.sqlite ./.mozilla/firefox/nfh217zw.default/cookies.sqlite How could this possibly happen? And more importantly: Why doesn't the btrfs stat(u)s output tell me that errors have occurred? $ sudo btrfs dev stats / [/dev/sda1].write_io_errs 0 [/dev/sda1].read_io_errs 0 [/dev/sda1].flush_io_errs 0 [/dev/sda1].corruption_errs 0 [/dev/sda1].generation_errs 0 If the filesystem health was monitored using btrfs dev stats (cronjob) (like checking a zpool using zpool status), the admin would not have been notified: $ sudo btrfs dev stats / | grep -v 0 -c 0 Is my understanding of the stats command wrong, does "corruption_errs" not mean corruption errors? -- Philip