From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id o4GNUWAL210137 for ; Sun, 16 May 2010 18:30:33 -0500 Received: from mail.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 096B7149731D for ; Sun, 16 May 2010 16:33:40 -0700 (PDT) Received: from mail.internode.on.net (bld-mail16.adl2.internode.on.net [150.101.137.101]) by cuda.sgi.com with ESMTP id p9lo72COatGt1wAh for ; Sun, 16 May 2010 16:33:40 -0700 (PDT) Date: Mon, 17 May 2010 09:32:43 +1000 From: Dave Chinner Subject: Re: xfs didn't provide redundancy for citical data structure? Message-ID: <20100516233243.GH8120@dastard> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: hank peng Cc: xfs-oss On Sat, May 15, 2010 at 11:57:51PM +0800, hank peng wrote: > I read this paper: http://pages.cs.wisc.edu/~vshree/xfs.pdf, which > says xfs didn't provide redundancy for citical data structure, such as > mirror, parity. I wonder if it is so? > If it is, is there plan to implement that for XFS developers? XFS assumes redundancy and protection against bit errors is done in the block layeri (i.e. RAID of some kind). Changing that assumption takes a lot of work and involves modifying the disk format, so can't be done overnight. That being said, work is in progress to make XFS more robust - see this page for ideas on how we are approaching the problem: http://xfs.org/index.php/Reliable_Detection_and_Repair_of_Metadata_Corruption I'll also point out that the above paper makes some fundamental mistakes (e.g. XFS does not use "data=ordered" journalling as they conclude it does from a limited observation). Hence the rest of their results are somewhat questionable, too, as we can't examine them closely enough to confirm or deny them.... Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs