From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Darrick J. Wong" Subject: Filesystem Mutation Tool Date: Fri, 04 Aug 2006 19:07:02 -0700 Message-ID: <44D3FD46.7070805@us.ibm.com> Reply-To: "Darrick J. Wong" Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from e3.ny.us.ibm.com ([32.97.182.143]:28895 "EHLO e3.ny.us.ibm.com") by vger.kernel.org with ESMTP id S1161508AbWHECHD (ORCPT ); Fri, 4 Aug 2006 22:07:03 -0400 Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by e3.ny.us.ibm.com (8.12.11.20060308/8.12.11) with ESMTP id k75273Fa029804 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL) for ; Fri, 4 Aug 2006 22:07:03 -0400 Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay02.pok.ibm.com (8.13.6/NCO/VER7.0) with ESMTP id k75272Nb287756 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Fri, 4 Aug 2006 22:07:03 -0400 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id k75272RM023641 for ; Fri, 4 Aug 2006 22:07:02 -0400 Received: from [9.47.17.97] (plum.beaverton.ibm.com [9.47.17.97]) by d01av03.pok.ibm.com (8.12.11.20060308/8.12.11) with ESMTP id k75272PE023636 for ; Fri, 4 Aug 2006 22:07:02 -0400 To: linux-fsdevel Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Hi all, As I might've mentioned to a few of you at OLS, I've hacked up a quick and dirty program to study the effects of what happens to a filesystem when certain blocks mutate underneath it (think malice, your RAID5 controller goes berserk, etc). Said program is now posted in a crude form here: http://sweaglesw.net/~djwong/programs/fs_mutate/ I've run this program against ext3 and reiserfs; so far, ext3 seems to be the stability winner, as it tends to stay up the longest (about 30-35 minutes) even with destroy mode turned on. reiserfs lasts a few minutes under such a beating. Of course, "stays up" is a long way from "works properly" -- overwriting things like indirect blocks has the rather amusing effect of generating lots of messages about falling off the end of a drive. As with the folks who used carefully crafted ISO9660 filesystems to crash arbitrary machines demonstrated last year, it's not so hard to get Linux to automount filesystems. To my knowledge, nobody's tried a similar thing against the other filesystems, though I could just be ignorant. What do you think? Useful tool? Or am I the one being the tool? ;) --D