From: "Daniel Taylor" Subject: breaking ext4 to test recovery Date: Mon, 28 Mar 2011 19:45:41 -0700 Message-ID: <25B374CC0D9DFB4698BB331F82CD0CF20D61B8@wdscexbe08.sc.wdc.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT To: Return-path: Received: from wdscspam3.wdc.com ([129.253.55.42]:56645 "EHLO wdscspam3.wdc.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753327Ab1C2C7M convert rfc822-to-8bit (ORCPT ); Mon, 28 Mar 2011 22:59:12 -0400 Content-class: urn:content-classes:message Sender: linux-ext4-owner@vger.kernel.org List-ID: I would like to be able to break our ext4 file system (specifically corrupt the journal) to be sure that we can automatically notice the problem and attempt an autonomous fix. dumpe2fs tells me the inode, but not, that I can see, the blocks where the journal exists (for "dd"ing junk to it). Is there any debug tool that would let me deliberately break the file system (at least, trash the journal)? If not, is there a hint for figuring out the block(s) of the journal so I can stomp it? The kernel is in an embedded machine, so it's a little old 2.6.32.11 and e2fsprogs/libs 1.41.12-2 (Lenny) Dan Taylor Sr. Staff Engineer WD Branded Products 949.672.7761