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 15:15:41 -0600 Sender: linux-fsdevel-owner@vger.kernel.org Message-ID: <20031024151541.Q17778@schatzie.adilger.int> References: <20031024143829.GB11277@delft.aura.cs.cmu.edu> <20031024141146.O17778@schatzie.adilger.int> <1067027088.16779.4.camel@patehci2> <20031024143802.P17778@schatzie.adilger.int> <1067028764.16779.13.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]:65519 "EHLO schatzie.adilger.int") by vger.kernel.org with ESMTP id S262633AbTJXVQW (ORCPT ); Fri, 24 Oct 2003 17:16:22 -0400 To: Pat LaVarre Content-Disposition: inline In-Reply-To: <1067028764.16779.13.camel@patehci2>; from p.lavarre@ieee.org on Fri, Oct 24, 2003 at 02:52:44PM -0600 List-Id: linux-fsdevel.vger.kernel.org On Oct 24, 2003 14:52 -0600, Pat LaVarre wrote: > "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?" > > Is there, as yet, no linux filesystem that preserves the integrity of > the data and metadata despite such failures? If I could write such an > fs on to a single directly-attached local drive, then I could measure > how often I myself experience such failures. > > I'm confident I actually do experience these failures because often I > work in comparative, raid-like measures. When I see one drive and > another disagree about what I wrote, then whenever I trust my write and > diff and read tools I must conclude one or both of the HDD's is wrong. I recall there being a loopback driver that will write a checksum for each block written to the device into a separate block device (probably just another loop device on a separate filesystem) so you could use that to verify your data on each read. Cheers, Andreas -- Andreas Dilger http://sourceforge.net/projects/ext2resize/ http://www-mddsp.enel.ucalgary.ca/People/adilger/