From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp1040.oracle.com ([156.151.31.81]:34624 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751037AbaJQICj (ORCPT ); Fri, 17 Oct 2014 04:02:39 -0400 Date: Fri, 17 Oct 2014 16:02:03 +0800 From: Liu Bo To: Tomasz Torcz , linux-btrfs@vger.kernel.org Subject: Re: unexplainable corruptions 3.17.0 Message-ID: <20141017080202.GA3604@localhost.localdomain> Reply-To: bo.li.liu@oracle.com References: <20141016091726.GA582640@mother.pipebreaker.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20141016091726.GA582640@mother.pipebreaker.pl> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Thu, Oct 16, 2014 at 11:17:26AM +0200, Tomasz Torcz wrote: > Hi, > > Recently I've observed some corruptions to systemd's journal > files which are somewhat puzzling. This is especially worrying > as this is btrfs raid1 setup and I expected auto-healing. > > System details: 3.17.0-301.fc21.x86_64 > btrfs: raid1 over 2x dm-crypted 6TB HDDs. > mount opts: rw,relatime,seclabel,compress=lzo,space_cache > > Broken files are in /var/log/journal directory. This directory > is set NOCOW with chattr, all the files within too. > > Example of broken file: > system@0005057fe87730cf-6d3d85ed59bd70ae.journal~ > > When read with dd_rescue, there are many I/O errors > reported, the summary looks like that (x = error): > >-..-..xxxxxxxxx---x.-..-..-...-..-..-...-< 100% > > Reads with cat, hexdump fails with: > read(4, 0x1001000, 65536) = -1 EIO (Input/output error) > > But btrfs dev stat reports no errors! > $ btrfs dev stat . > [/dev/dm-0].write_io_errs 0 > [/dev/dm-0].read_io_errs 0 > [/dev/dm-0].flush_io_errs 0 > [/dev/dm-0].corruption_errs 0 > [/dev/dm-0].generation_errs 0 > [/dev/dm-1].write_io_errs 0 > [/dev/dm-1].read_io_errs 0 > [/dev/dm-1].flush_io_errs 0 > [/dev/dm-1].corruption_errs 0 > [/dev/dm-1].generation_errs 0 > > There are no hardware errors in dmesg. > > This is perplexing. How to find out what is causing the > brokeness and howto avoid it in the future? Does scrub work for you? thanks, -liubo > > -- > Tomasz .. oo o. oo o. .o .o o. o. oo o. .. > Torcz .. .o .o .o .o oo oo .o .. .. oo oo > o.o.o. .o .. o. o. o. o. o. o. oo .. .. o. > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html