From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935763AbWLHJQs (ORCPT ); Fri, 8 Dec 2006 04:16:48 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S938017AbWLHJQs (ORCPT ); Fri, 8 Dec 2006 04:16:48 -0500 Received: from enyo.dsw2k3.info ([195.71.86.239]:55934 "EHLO enyo.dsw2k3.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935763AbWLHJQr (ORCPT ); Fri, 8 Dec 2006 04:16:47 -0500 Message-ID: <45792D74.5000901@citd.de> Date: Fri, 08 Dec 2006 10:16:36 +0100 From: Matthias Schniedermeyer User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.5) Gecko/20041217 Mnenhy/0.7 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Pete Zaitcev 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 References: <45786E58.5070308@citd.de> <20061207154545.6eb516c4.zaitcev@redhat.com> In-Reply-To: <20061207154545.6eb516c4.zaitcev@redhat.com> 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 Pete Zaitcev wrote: > 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), That would definetly cost way to much money and time to be in any way "efficient". > and also use decent cables. I replaced all cables with "High Quality"-cables. But as a "Joe user" it is practically impossible to really know if the cables are good. All i can say is that the "original" cables that came with the enclosures appear a bit thin and the ones i bought appear much more thick, have gold plated contacts and have a massive plaited shielding IOW appear much more trustworthy. But, as i said, in the end i can't really know if they are better than the original ones. Bis denn -- Real Programmers consider "what you see is what you get" to be just as bad a concept in Text Editors as it is in women. No, the Real Programmer wants a "you asked for it, you got it" text editor -- complicated, cryptic, powerful, unforgiving, dangerous.