From owner-freebsd-current@FreeBSD.ORG Sun Sep 13 18:13:09 2009 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 67118106566B; Sun, 13 Sep 2009 18:13:09 +0000 (UTC) (envelope-from rmacklem@uoguelph.ca) Received: from esa-annu.mail.uoguelph.ca (esa-annu.mail.uoguelph.ca [131.104.91.36]) by mx1.freebsd.org (Postfix) with ESMTP id 069228FC0C; Sun, 13 Sep 2009 18:13:08 +0000 (UTC) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AjIFAEfTrEqDaFvG/2dsb2JhbACQPgHHcoQYBYFW X-IronPort-AV: E=Sophos;i="4.44,379,1249272000"; d="scan'208";a="46123651" Received: from amazon.cs.uoguelph.ca ([131.104.91.198]) by esa-annu-pri.mail.uoguelph.ca with ESMTP; 13 Sep 2009 14:13:08 -0400 Received: from localhost (localhost.localdomain [127.0.0.1]) by amazon.cs.uoguelph.ca (Postfix) with ESMTP id F1E2C2100BD; Sun, 13 Sep 2009 14:13:07 -0400 (EDT) X-Virus-Scanned: amavisd-new at amazon.cs.uoguelph.ca Received: from amazon.cs.uoguelph.ca ([127.0.0.1]) by localhost (amazon.cs.uoguelph.ca [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id qOc3nrfEjsKu; Sun, 13 Sep 2009 14:13:07 -0400 (EDT) Received: from muncher.cs.uoguelph.ca (muncher.cs.uoguelph.ca [131.104.91.102]) by amazon.cs.uoguelph.ca (Postfix) with ESMTP id 303A721009D; Sun, 13 Sep 2009 14:13:07 -0400 (EDT) Received: from localhost (rmacklem@localhost) by muncher.cs.uoguelph.ca (8.11.7p3+Sun/8.11.6) with ESMTP id n8DIIPf17114; Sun, 13 Sep 2009 14:18:25 -0400 (EDT) X-Authentication-Warning: muncher.cs.uoguelph.ca: rmacklem owned process doing -bs Date: Sun, 13 Sep 2009 14:18:25 -0400 (EDT) From: Rick Macklem X-X-Sender: rmacklem@muncher.cs.uoguelph.ca To: freebsd-current@freebsd.org Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-fs@freebsd.org, doug@polands.org, qing.li@bluecoat.com Subject: NFS client defaults to a mix of UDP and TCP X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 13 Sep 2009 18:13:09 -0000 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