From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from magic.merlins.org ([209.81.13.136]:42717 "EHLO mail1.merlins.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752841AbcCGPNa (ORCPT ); Mon, 7 Mar 2016 10:13:30 -0500 Received: from [12.139.153.2] (port=50204 helo=legolas.merlins.org) by mail1.merlins.org with esmtpsa (Cipher TLS1.2:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.80 #2) id 1acwqf-0002kI-Jp by authid with srv_auth_plain for ; Mon, 07 Mar 2016 07:13:29 -0800 Received: from merlin by legolas.merlins.org with local (Exim 4.80) (envelope-from ) id 1acwqe-0005bf-I9 for linux-btrfs@vger.kernel.org; Mon, 07 Mar 2016 07:13:28 -0800 Date: Mon, 7 Mar 2016 07:13:28 -0800 From: Marc MERLIN To: linux-btrfs@vger.kernel.org Subject: Re: Documentation for BTRFS error (device dev): bdev /dev/xx errs: wr 22, rd 0, flush 0, corrupt 0, gen 0 Message-ID: <20160307151328.GF29369@merlins.org> References: <20160223215911.GA13811@merlins.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20160223215911.GA13811@merlins.org> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Tue, Feb 23, 2016 at 01:59:11PM -0800, Marc MERLIN wrote: > I have a freshly created md5 array, with drives that I specifically > scanned one by one block by block, and for good measure, I also scanned > the entire software raid with a check command which took 3 days to run. > > Everything passed. > > Then, I made a bcache of that device, an ssd that seems to work fine > otherwise (brand new), and dmcrypted the result > > md5 - bache - dmcrypt - btrfs > ssd / > > Now, I'm copying data over with btrfs send, and I'm seeing these slowly > show up and the write counter go up one by one. > BTRFS error (device dm-7): bdev /dev/mapper/oldds1 errs: wr 17, rd 0, flush 0, corrupt 0, gen 0 > > Where is the documentation for those counters? > Is the write error fatal, or a recovered error? > Should I consider that my filesystem is corrupted as soon as any of > those counters go up? > (I couldn't find an exact meaning of each of them) > Sadly, this problem hasn't gone away [ 2381.333412] BTRFS error (device dm-5): bdev /dev/mapper/oldds1 errs: wr 298, rd 0, flush 0, corrupt 0, gen 0 I'm really trying to make sense out of it. Are those recovered errors (bad IO, command was retried, things worked after that), fatal errors (data loss) That md5 is in a disk shelf at the end of a longish esata cable. It's possible that the cable is bad, or it couuld be something else entirely. I'm still trying to understand the error so that I can diagnose and address it properly. 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/ | PGP 1024R/763BE901