From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932131AbVJHEj5 (ORCPT ); Sat, 8 Oct 2005 00:39:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932135AbVJHEj5 (ORCPT ); Sat, 8 Oct 2005 00:39:57 -0400 Received: from xproxy.gmail.com ([66.249.82.196]:1829 "EHLO xproxy.gmail.com") by vger.kernel.org with ESMTP id S932131AbVJHEj5 convert rfc822-to-8bit (ORCPT ); Sat, 8 Oct 2005 00:39:57 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=DI/7ZwifVj1GLLoeF7MA40kcJdsmgziD8Fnjz6lySX6nFC2ylgs0pYPhJC7YWjaEI+qmCS0vQe+F7qgRZz3XWDEGEL3cqzfwnrVpj2C1KL0+76gLN0cEKsSsG0NbYJYatHl/xv7Y4j0CBryAnUuN7nRcnbbsE3unOHa5AwwOjbY= Message-ID: <4ae3c140510072139n68b9b2eeyc0a400be32d958fe@mail.gmail.com> Date: Sat, 8 Oct 2005 00:39:56 -0400 From: Xin Zhao Reply-To: Xin Zhao To: linux-kernel@vger.kernel.org Subject: why is NFS performance poor when decompress linux kernel MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, I setup two virtual machines. One works as NFS server and the other is client. They talk to each other via in-host network communication. I noticed that when doing large file copy or linux kernel compilation in a NFS direcotry, the performance is not bad compared to local disk filesystem such as ext2. However, if I do linux kernel tarball decompression on a NFS directory, the performance is much worse than local disk filesystem (over 3 times slower). Anybody know the reason? My guess is that NFS has to do lookup and getattr over the network, while local disk filesystem can do that in local memory. Is this the major reason? or there are some other reasons? Thanks for help! -x