From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Dilger Subject: Re: srfs - a new file system. Date: Fri, 24 Oct 2003 14:38:02 -0600 Sender: linux-fsdevel-owner@vger.kernel.org Message-ID: <20031024143802.P17778@schatzie.adilger.int> References: <20031024143829.GB11277@delft.aura.cs.cmu.edu> <20031024141146.O17778@schatzie.adilger.int> <1067027088.16779.4.camel@patehci2> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: tzachar@cs.bgu.ac.il, jaharkes@cs.cmu.edu, bulb@ucw.cz, linux-fsdevel@vger.kernel.org Return-path: Received: from h68-147-142-75.cg.shawcable.net ([68.147.142.75]:41455 "EHLO schatzie.adilger.int") by vger.kernel.org with ESMTP id S262601AbTJXUil (ORCPT ); Fri, 24 Oct 2003 16:38:41 -0400 To: Pat LaVarre Content-Disposition: inline In-Reply-To: <1067027088.16779.4.camel@patehci2>; from p.lavarre@ieee.org on Fri, Oct 24, 2003 at 02:24:48PM -0600 List-Id: linux-fsdevel.vger.kernel.org On Oct 24, 2003 14:24 -0600, Pat LaVarre wrote: > > > a one to 10^gazillion chance of this happening, > > > > So, system stabilizes when there are no files left ;-). > > Anyone have a measure of how often these events actually do occur? > > What little I've seen people say of how they design file and RAID > systems speaks as if HDD's reliably chose either to read back what you > wrote to them or else reported an error. > > What about when the HDD actually reads back something else? > > How can we know how commonly that occurs in practice, so that we can > know how often we're wrong to believe such things as our locally > recorded vector time? There are lots of ways to read back garbage from a disk unrelated to physical HDD errors: memory errors, bad cables, software errors (driver, fs, vm, etc), bad IDE DMA settings, power failures during write, etc... Cheers, Andreas -- Andreas Dilger http://sourceforge.net/projects/ext2resize/ http://www-mddsp.enel.ucalgary.ca/People/adilger/