From owner-freebsd-fs@FreeBSD.ORG Mon Sep 14 13:13:39 2009 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 1DBF21065672; Mon, 14 Sep 2009 13:13:39 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id DFC0D8FC19; Mon, 14 Sep 2009 13:13:38 +0000 (UTC) Received: from bigwig.baldwin.cx (66.111.2.69.static.nyinternet.net [66.111.2.69]) by cyrus.watson.org (Postfix) with ESMTPSA id 931AD46B06; Mon, 14 Sep 2009 09:13:38 -0400 (EDT) Received: from jhbbsd.hudson-trading.com (unknown [209.249.190.8]) by bigwig.baldwin.cx (Postfix) with ESMTPA id A9C268A01F; Mon, 14 Sep 2009 09:13:36 -0400 (EDT) From: John Baldwin To: freebsd-current@freebsd.org Date: Mon, 14 Sep 2009 08:58:33 -0400 User-Agent: KMail/1.9.7 References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200909140858.34592.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.0.1 (bigwig.baldwin.cx); Mon, 14 Sep 2009 09:13:37 -0400 (EDT) X-Virus-Scanned: clamav-milter 0.95.1 at bigwig.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-2.5 required=4.2 tests=AWL,BAYES_00,RDNS_NONE autolearn=no version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on bigwig.baldwin.cx Cc: freebsd-fs@freebsd.org, qing.li@bluecoat.com Subject: Re: NFS client defaults to a mix of UDP and TCP 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, 14 Sep 2009 13:13:39 -0000 On Sunday 13 September 2009 2:18:25 pm Rick Macklem wrote: > I had thought that I had posted w.r.t. before, but can't find it in > the archive (which might explain why I didn't get any responses:-). > > The current mount_nfs defaults to using UDP for the mount protocol > and then switches to using TCP for the actual mount. (When neither > "udp" nor "tcp" mount options are specified.) I don't think I > changed it to be this way, because I recall noticing it when I > added changes for the experimental NFS client and thought it was > "weird", but assumed that it had been that way for a long time. > > It now appears that it was introduced post-FreeBSD7 at r176198, > which changed the default for NFS to TCP, but didn't switch the > default for the mount protocol to TCP. > > The ancient history of this is that "once upon a time" there were > NFS servers that could do NFS over TCP, but only supported UDP for > the mount protocol and there was an option called "mntudp" for that > case. I can't imagine that any server still needs this case, but > it appears to have become the default. > > The default works fine for servers that support both UDP and TCP, > but result in a non-functional mount point when the server only > supports UDP. (See recent email thread on freebsd-stable called > "NFS issues on 8.0-BETA4".) > > Is this something that should be changed? rick Yes. I know of folks would love to have NFS use only TCP, including the initial RPC portmapper requests. IMO an NFS mount should use TCP for everything and a UDP mount should use UDP for everything by default. -- John Baldwin