From mboxrd@z Thu Jan 1 00:00:00 1970 From: Trond Myklebust Subject: Re: NFS synchronization problems on Beowulf cluster Date: Mon, 17 Jul 2006 14:49:18 -0400 Message-ID: <1153162159.13961.3.camel@localhost> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: nfs@lists.sourceforge.net Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list2-new.sourceforge.net with esmtp (Exim 4.43) id 1G2Y9w-0003Ju-AM for nfs@lists.sourceforge.net; Mon, 17 Jul 2006 11:49:37 -0700 Received: from pat.uio.no ([129.240.10.4] ident=7411) by mail.sourceforge.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.44) id 1G2Y9w-0003tu-75 for nfs@lists.sourceforge.net; Mon, 17 Jul 2006 11:49:36 -0700 To: Mario Storti In-Reply-To: List-Id: "Discussion of NFS under Linux development, interoperability, and testing." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nfs-bounces@lists.sourceforge.net Errors-To: nfs-bounces@lists.sourceforge.net On Mon, 2006-07-17 at 15:17 -0300, Mario Storti wrote: > Hi all, > > We have still problems with NFS in our Beowulf cluster. The original > post is here > > http://thread.gmane.org/gmane.linux.nfs/9564/focus=9566 > > The news are that we reproduced the problem on Scientific Linux 4.2 > and also without VNFS. In addition we have taken a tethereal capture > that may help in understanding the problem. > > In brief we have a Beowulf class cluster built on Scientific Linux > (Beryllium) 4.2, (kernel 2.6.9-22.0.1). The cluster is disk-less > (nodes don't have hard disks) based on the Warewulf package. NFS > traffic is reduced by using VNFS filesystems at the nodes. However we > reproduced the problem in a configuration with disks at the nodes. > > The problem is that for some files in user accounts if we make some > modifications to the file in the server, this changes are not seen in > the compute nodes. The NFS server is NFS3 and with the standard > configuration (8 instances of the server and default parameters). The > cluster has 20 nodes at this time, but we have made experiments with a > `cloned' cluster and even with only two nodes the problem persist. > > The experiment is as follows: We change a text file in a user account > with Emacs and checking whether the change is seen in the compute > nodes. Sometimes the change is immediately seen in the compute nodes, > but many times some nodes don't see the change. > This is a FAQ that has been well-publicised and discussed to death on this list: http://nfs.sourceforge.net/#faq_a8 Trond ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs