From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Dilger Subject: Re: why not allow checksumming of file contents, too? Date: Thu, 12 Jun 2008 23:08:39 -0600 Message-ID: <20080613050839.GT3726@webber.adilger.int> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7BIT Cc: linux-ext4@vger.kernel.org To: iaw4 Return-path: Received: from sca-es-mail-2.Sun.COM ([192.18.43.133]:60379 "EHLO sca-es-mail-2.sun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751442AbYFMFIm (ORCPT ); Fri, 13 Jun 2008 01:08:42 -0400 Received: from fe-sfbay-09.sun.com ([192.18.43.129]) by sca-es-mail-2.sun.com (8.13.7+Sun/8.12.9) with ESMTP id m5D58f0G020237 for ; Thu, 12 Jun 2008 22:08:41 -0700 (PDT) Received: from conversion-daemon.fe-sfbay-09.sun.com by fe-sfbay-09.sun.com (Sun Java System Messaging Server 6.2-8.04 (built Feb 28 2007)) id <0K2D00J01Y5E0U00@fe-sfbay-09.sun.com> (original mail from adilger@sun.com) for linux-ext4@vger.kernel.org; Thu, 12 Jun 2008 22:08:41 -0700 (PDT) In-reply-to: Content-disposition: inline Sender: linux-ext4-owner@vger.kernel.org List-ID: On Jun 13, 2008 01:33 +0000, iaw4 wrote: > there is already checksumming of metadata. There is only checksumming of the metadata in the journal and for the group descriptor. There is not yet checksumming of the rest of metadata (bitmaps, inode table, superblock, etc). > having a file-system option of > checksumming every file's contents upon closing the write would be very > convenient, too. It would only take an extra few bytes in the file > descriptor, wouldn't it? It would be nice insurance against hardware > corruption. zfs has it, too, I believe. just a suggestions from someone > who is just an end user... Sure, I don't think anyone objects to it, but it is a lot of work to implement and nobody has yet made the effort to do so. If someone is looking to work on this, we've given a lot of thought to the design of how to implement this. Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc.