From owner-freebsd-stable@FreeBSD.ORG  Wed Jul  5 21:53:51 2006
Return-Path: <owner-freebsd-stable@FreeBSD.ORG>
X-Original-To: freebsd-stable@freebsd.org
Delivered-To: freebsd-stable@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 0D86516A4DF;
	Wed,  5 Jul 2006 21:53:51 +0000 (UTC)
	(envelope-from lists@stringsutils.com)
Received: from zoraida.natserv.net (p65-147.acedsl.com [66.114.65.147])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 4D29343D69;
	Wed,  5 Jul 2006 21:53:42 +0000 (GMT)
	(envelope-from lists@stringsutils.com)
Received: from zoraida.natserv.net (localhost.natserv.net [127.0.0.1])
	by zoraida.natserv.net (Postfix) with ESMTP id 78925B833;
	Wed,  5 Jul 2006 17:53:40 -0400 (EDT)
X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on zoraida.natserv.net
X-Spam-Level: 
X-Spam-Status: No, score=0.0 required=5.0 tests=none autolearn=failed 
	version=3.1.3
Received: from zoraida.natserv.net (zoraida.natserv.net [66.114.65.147])
	by zoraida.natserv.net (Postfix) with ESMTP id 25A51B822;
	Wed,  5 Jul 2006 17:53:40 -0400 (EDT)
References: <E1FxzUU-000MMw-5m@cs1.cs.huji.ac.il>
	<20060705100403.Y80381@fledge.watson.org>
Message-ID: <cone.1152136419.991036.72616.1000@zoraida.natserv.net>
X-Mailer: http://www.courier-mta.org/cone/
From: Francisco Reyes <lists@stringsutils.com>
To: Robert Watson <rwatson@FreeBSD.org>
Date: Wed, 05 Jul 2006 17:53:39 -0400
Mime-Version: 1.0
Content-Type: text/plain; format=flowed; charset="US-ASCII"
Content-Disposition: inline
Content-Transfer-Encoding: 7bit
X-Virus-Scanned: ClamAV using ClamSMTP
Cc: freebsd-stable@freebsd.org, Michel Talon <talon@lpthe.jussieu.fr>
Subject: Re: NFS Locking Issue
X-BeenThere: freebsd-stable@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Production branch of FreeBSD source code <freebsd-stable.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>, 
	<mailto:freebsd-stable-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-stable>
List-Post: <mailto:freebsd-stable@freebsd.org>
List-Help: <mailto:freebsd-stable-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>,
	<mailto:freebsd-stable-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 05 Jul 2006 21:53:51 -0000

Robert Watson writes:

> can you trigger it using work on just one client against a server, without 
> client<->client interactions?  This makes tracking and reproduction a lot 
> easier

Personally I am experiencing two problems.
1- NFS clients freeze/hang if the server goes away.
We have clients with several mounts so if one of the servers dies then the 
entire operation of the client is put in jeopardy.

This I can reproduce every single time with a 6.X client.. with both a 5.X 
and a 6.X server.

"umount -f" hangs too.


> as multi-client test cases are really tricky! 

The second case only happens under heavy load and restarting nfsd makes it 
go away. Basically 'b' column in vmstat goes high and the performnance of 
the machine falls to the floor.

Going to try 
http://www.freebsd.org/doc/en_US.ISO8859-1/books/developers-handbook/kerneld 
ebug-deadlocks.html

And reading up on how to debug with DDB. Have another user who volunteered 
to give me some pointers.. so will try that.. so I am able to actually 
produce more helpfull info.