From owner-freebsd-fs@FreeBSD.ORG Mon Oct 17 09:10:26 2005 Return-Path: X-Original-To: freebsd-fs@FreeBSD.org Delivered-To: freebsd-fs@FreeBSD.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id DA7C216A41F for ; Mon, 17 Oct 2005 09:10:26 +0000 (GMT) (envelope-from rebehn@ant.uni-bremen.de) Received: from antsrv1.ant.uni-bremen.de (antsrv1.ant.uni-bremen.de [134.102.176.16]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6176043D46 for ; Mon, 17 Oct 2005 09:10:25 +0000 (GMT) (envelope-from rebehn@ant.uni-bremen.de) Received: from bremerhaven.ant.uni-bremen.de ([134.102.176.10]) by antsrv1.ant.uni-bremen.de with esmtp (Exim 4.54 (FreeBSD)) id 1ERR0i-000F3G-T3; Mon, 17 Oct 2005 11:10:25 +0200 Message-ID: <43536A80.2040502@ant.uni-bremen.de> Date: Mon, 17 Oct 2005 11:10:24 +0200 From: Heinrich Rebehn User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.8) Gecko/20050831 Debian/1.7.8-1sarge2 X-Accept-Language: en MIME-Version: 1.0 To: Nicolas KOWALSKI References: <20051014160128.hev160v52ossokg0@wwws.cs.ait.ac.th> <20051014045824.V5343@odysseus.silby.com> <434FD761.3050506@centtech.com> <434FEDC6.4040405@centtech.com> <434FFAD6.6000002@ant.uni-bremen.de> In-Reply-To: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: freebsd-fs@FreeBSD.org Subject: Re: FreeBSD NFS server not responding to TCP SYN packets from Linux/SunOS clients X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 17 Oct 2005 09:10:27 -0000 Nicolas KOWALSKI wrote: > Heinrich Rebehn writes: > > >>Nicolas KOWALSKI wrote: >> >>>Eric Anderson writes: >>> >>> >>>>Nicolas KOWALSKI wrote: >>>> >>>> >>>>>Eric Anderson writes: >>>>> >>>>> >>>>>>Nicolas KOWALSKI wrote: >>>>>> >>>>>> >>>>>>>Mike Silbersack writes: >>>>>>> >>>>>>> >>>>>>>>Actually, there may be a quick fix for this specific machine. >>>>>>>>If you set net.inet.tcp.keepidle to 1 minute (60*whatever >>>>>>>>kern.hz is), that'll cause keepalive packets to be sent every >>>>>>>>minute to an idle connection, rather than every 2 hours. That >>>>>>>>would kill the stuck connections much quicker. >>>>> >>>>>>>Unfortunately, this does not work as expected. I just tested >>>>>>>with my workstation (Linux 2.6), with NFS filesystems mounted >>>>>>>with TCP; when the station rebooted abruptely, mounting the same >>>>>>>NFS filesystems hung more than 1 minute (15 minutes just >>>>>>>now). During this hang, I saw on the server, using netstat, the >>>>>>>nfsd process related to my workstation in ESTABLISHED state. >>>>>> >>>>>>Man fixmount? >>>>> >>>>>This is a FreeBSD-only command apparently. I did not find it on >>>>>Linux or Solaris. It could have been useful, by calling it before >>>>>NFS filesystems are mounted on clients, yes. >>>> >>>>It's available on Fedora Core 2 and 3 at least. > > >>>So, its a non-option, because we are only using Debian Sarge and >>>Solaris 9 UNIX workstations. :-( >> >>For Debian Sarge, it is in am-utils (amd automounter). > > > Oh, thanks for the information... > > >>Since we are bit by the same problem - we have diskless Linux >>clients that mount their root fs from a FreeBSD server, which >>sometimes takes some 15 minutes - i will try fixmount next week. > > > I just tried it without success. I call it just before > /etc/rcS.d/S45mountnfs, and it does not help. > > It looks "normal" for me, because the hang (visible on the etherreal > trace) does not happen at mount call, but when requesting the SYN to > the nfsd port on the server. > Oh, that is bad news. But might it be possible to write a small program on the client side that would tell the server to close the connection? Unfortunately my network programming knowledge is very limitied, but if someone could give me an idea, i would be willing to experiment. After all, this is a very annoying problem :-( --Heinrich