From: Jan Kara Subject: Re: Weird I/O errors with USB hard drive not remounting filesystem readonly Date: Mon, 23 Nov 2009 11:54:40 +0100 Message-ID: <20091123105440.GB15679@duck.suse.cz> References: <20091113050907.GA4965@roll> <20091119160700.GC2943@atrey.karlin.mff.cuni.cz> <20091120082359.GA29538@roll> <20091120094641.GB15422@duck.suse.cz> <20091123080919.GA3115@roll> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Jan Kara , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, Jens Axboe , linux-scsi@vger.kernel.org, linux-ext4@vger.kernel.org To: tmhikaru@gmail.com Return-path: Received: from cantor.suse.de ([195.135.220.2]:45245 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756652AbZKWKyf (ORCPT ); Mon, 23 Nov 2009 05:54:35 -0500 Content-Disposition: inline In-Reply-To: <20091123080919.GA3115@roll> Sender: linux-ext4-owner@vger.kernel.org List-ID: Hi, On Mon 23-11-09 03:09:19, tmhikaru@gmail.com wrote: > Okay, finally had some time to dismantle the machine in question and > inserted the backup drive without the enclosure. Now that I was able to get > smartctl to give me information on what was going on, it seems there's > nothing wrong with the drive itself (no remapped sectors, nothing prefail or > fail going wrong, drive's smart status is good) but it's had a history of > 406 (!!!) errors reported, the last five happening within the same second, > all of which seem (to my untrained eye) to imply a bad IDE cable. Which > means likely my USB enclosure is screwing up. > > To be sure, I did some extended testing with it hooked up: Tried > doing a full and incremental backup of my machine with no errors reported, > as well as an offline and then immediately afterwards, long test via > smartctl. Nothing changed in the output. Yeah, from what you write, it looks like USB enclosure is at fault (or it could still be your USB controller but I doubt it). It's still a bit bothering that the error reported by the drive was not properly propagated up to VFS. Either it's some block layer retry/ignore magic that I missed or we ignore errors from block layer in some place. Honza -- Jan Kara SUSE Labs, CR