From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1164015AbWLGXqh (ORCPT ); Thu, 7 Dec 2006 18:46:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1164014AbWLGXqh (ORCPT ); Thu, 7 Dec 2006 18:46:37 -0500 Received: from mx1.redhat.com ([66.187.233.31]:53273 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1164015AbWLGXqg (ORCPT ); Thu, 7 Dec 2006 18:46:36 -0500 Date: Thu, 7 Dec 2006 15:45:45 -0800 From: Pete Zaitcev To: Matthias Schniedermeyer Cc: usb-storage@lists.one-eyed-alien.net, linux-kernel@vger.kernel.org Subject: Re: single bit errors on files stored on USB-HDDs via USB2/usb_storage Message-Id: <20061207154545.6eb516c4.zaitcev@redhat.com> In-Reply-To: <45786E58.5070308@citd.de> References: <45786E58.5070308@citd.de> Organization: Red Hat, Inc. X-Mailer: Sylpheed version 2.2.10 (GTK+ 2.10.6; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 07 Dec 2006 20:41:12 +0100, Matthias Schniedermeyer wrote: > >>I'm using a Bunch auf HDDs in USB-Enclosures for storing files. > >>(currently 38 HDD, with a total capacity of 9,5 TB of which 8,5 TB is used) > >>[....] > >>This time i kept the defective files and used "vbindiff" to show me the > >>difference. Strangly in EVERY case the difference is a single bit in a > >>sequence of "0xff"-Bytes inside a block of varing bit-values that > >>changed a "0xff" into a "0xf7". > > This was almost certainly caused by hardware flaws in the USB interface > > chips of the enclosures. There's nothing the kernel can do about it > > because the errors aren't reported; all that happens is that incorrect > > data is sent to or from the drive. > > So pretty much all ich can do is to pray that the errors don't corrupt > the Filesystem-Metadata (XFS). No, this is not all. You should buy a variety of different enclosures with different chipsets (e.g. find a Freecom if you can), and also use decent cables. -- Pete