From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bronze.cs.yorku.ca ([130.63.90.34]:33273 "EHLO bronze.cs.yorku.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753150Ab0G1OXf (ORCPT ); Wed, 28 Jul 2010 10:23:35 -0400 Received: from [130.63.86.125] (ident=jas) by bronze.cs.yorku.ca with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.67) (envelope-from ) id 1Oe6wC-00006D-A8 for linux-nfs@vger.kernel.org; Wed, 28 Jul 2010 09:44:48 -0400 Message-ID: <4C503450.1010609@cse.yorku.ca> Date: Wed, 28 Jul 2010 09:44:48 -0400 From: Jason Keltz To: linux-nfs@vger.kernel.org Subject: hang on existing systems when exporting NFS share to new systems Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Hi. My list of NFS exports has been gradually growing over the years. Right now, for example, my home directories are exported to around 800 hosts. (although only a relatively small subset of those will mount at the same time...). I used to just add hosts to /etc/exports on the file server, and run "exportfs -r", and everything would be fine. New systems would be able to mount everything perfectly, and existing systems would not be affected at all. As the list has grown, I've been noticing a problem. Now, when I run exportfs -r, there is an approximate 7-10 second hang on the systems that have already mounted the share, and then everything returns to normal. This doesn't happen *while* exportfs -r is running, but just after it exits. I figured that maybe exportfs was "unexporting"/re-exporting to hosts that already had the share in use which might have caused the problem, so I tried to manually add/remove hosts thinking that this would only affect those hosts, but it did not. Exporting to one new host still causes the hang on all existing hosts. Since I have multiple exports to all of the hosts, adding one new host can hang things for a while. I can see that reducing the list of exports, or hosts would reduce the delay. What I am wondering is if there is a better way that I can add hosts without affecting connectivity to existing hosts? The NFS server itself is pretty powerful -- dual quad core box, lots of memory, many NFS threads, exclusive NFS server, etc... I am running an older RHEL4 release though, so it would have an older kernel/NFS system. Maybe this issue has been solved in newer releases. Any feedback would be helpful. Thanks! Jason.