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 nBPGECs3197190 for ; Fri, 25 Dec 2009 10:14:12 -0600 Received: from thunker.thunk.org (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 5E086E9AACF for ; Fri, 25 Dec 2009 08:14:56 -0800 (PST) Received: from thunker.thunk.org (thunk.org [69.25.196.29]) by cuda.sgi.com with ESMTP id Gifke8knooBff4HF for ; Fri, 25 Dec 2009 08:14:56 -0800 (PST) Date: Fri, 25 Dec 2009 11:14:53 -0500 From: tytso@mit.edu Subject: Re: [Jfs-discussion] benchmark results Message-ID: <20091225161453.GD32757@thunk.org> References: <19251.26403.762180.228181@tree.ty.sabi.co.uk> <20091224212756.GM21594@thunk.org> 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: Christian Kujau Cc: jfs-discussion@lists.sourceforge.net, linux-nilfs@vger.kernel.org, xfs@oss.sgi.com, reiserfs-devel@vger.kernel.org, Peter Grandi , ext-users , linux-ext4@vger.kernel.org, linux-btrfs@vger.kernel.org On Thu, Dec 24, 2009 at 05:52:34PM -0800, Christian Kujau wrote: > > Well, I do "sync" after each operation, so the data should be on disk, but > that doesn't mean it'll clear the filesystem buffers - but this doesn't > happen that often in the real world too. Also, all filesystem were tested > equally (I hope), yet some filesystem perform better than another - even > if all the content copied/tar'ed/removed would perfectly well fit into the > machines RAM. Did you include the "sync" in part of what you timed? Peter was quite right --- the fact that the measured bandwidth in your "cp" test is five times faster than the disk bandwidth as measured by hdparm, and many file systems had exactly the same bandwidth, makes me very suspicious that what was being measured was primarily memory bandwidth --- and not very useful when trying to measure file system performance. - Ted _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs