From: Ric Wheeler Subject: Re: Regular ext4 error warning with HD in USB dock Date: Sat, 01 Jan 2011 12:20:04 -0500 Message-ID: <4D1F6244.7050203@redhat.com> References: <201012280953.46149.kernel@kolivas.org> <20101228025343.GD10149@thunk.org> <20101228081917.GA1351@bitwizard.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "Ted Ts'o" , Rogier Wolff , Con Kolivas , linux-kernel@vger.kernel.org, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-usb@vger.kernel.org To: Amir Goldstein Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On 12/28/2010 05:30 AM, Amir Goldstein wrote: > On Tue, Dec 28, 2010 at 10:19 AM, Rogier Wolff wrote: >> On Mon, Dec 27, 2010 at 09:53:43PM -0500, Ted Ts'o wrote: >>> On Tue, Dec 28, 2010 at 09:53:45AM +1100, Con Kolivas wrote: >>>> [1048401.773270] EXT4-fs (sde8): mounted filesystem with writeback data mode. >>>> Opts: (null) >>>> [1048702.736011] EXT4-fs (sde8): error count: 3 >>>> [1048702.736016] EXT4-fs (sde8): initial error at 1289053677: >>>> ext4_journal_start_sb:251 >>>> [1048702.736018] EXT4-fs (sde8): last error at 1289080948: ext4_put_super:719 >>> That's actually not an error. It's a report which is generated every >>> 24 hours, indicating that there has been 3 errors since the last time >>> the error count has been cleared, with the first error taking place at >>> Sat Nov 6 10:27:57 2010 (US/Eastern) in the function >>> ext4_journal_start_sb(), at line 251, and the most recent error taking >>> place at Sat Nov 6 18:02:28 2010 (US/Eastern), in the function >>> ext4_put_super() at line 719. This is a new feature which was added >>> in 2.6.36. >> Nice. But the issue you're not mentioning is: What errors could have >> happened on the 6th of november? Should Con worry about those errors? >> > Ted, > > I would like to use this opportunity to remind you about my > record_journal_errstr() > implementation, see: > https://github.com/amir73il/ext4-snapshots/blob/next3-stable/fs/next3/super.c#L157 > > It records the initial errors messages (which I found to be the most > interesting), > in a message buffer on the unused space after the journal super block > (3K on a 4K block fs). > > fsck prints out those messages and clears the buffer. > In under a year of Next3 fs in beta and production, it has helped me many times > to analyse bugs post-mortem and find the problem. > > If there is demand, I can post the patch for Ext4. > > Amir. I do think that this sounds like a useful addition - should be very useful in doing post mortem analysis... Thanks! Ric