From owner-freebsd-fs@FreeBSD.ORG Tue Jan 31 05:29:27 2012 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 DB647106566C for ; Tue, 31 Jan 2012 05:29:27 +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 919DE8FC08 for ; Tue, 31 Jan 2012 05:29:27 +0000 (UTC) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Ap4EAFJ7J0+DaFvO/2dsb2JhbABDhQuqXYFyAQEFI1YbDgoCAg0ZAlkGrzWRdYEviVMBBQICHQMEAQ4BCAUDAwkNEoJxAgYFAgQMBg0DCQICcxkCBIIjgRYEiECMXpJw X-IronPort-AV: E=Sophos;i="4.71,594,1320642000"; d="scan'208";a="154396201" Received: from erie.cs.uoguelph.ca (HELO zcs3.mail.uoguelph.ca) ([131.104.91.206]) by esa-annu-pri.mail.uoguelph.ca with ESMTP; 31 Jan 2012 00:29:26 -0500 Received: from zcs3.mail.uoguelph.ca (localhost.localdomain [127.0.0.1]) by zcs3.mail.uoguelph.ca (Postfix) with ESMTP id 7CECBB3F24; Tue, 31 Jan 2012 00:29:26 -0500 (EST) Date: Tue, 31 Jan 2012 00:29:26 -0500 (EST) From: Rick Macklem To: Jeremy Chadwick Message-ID: <1413501962.445071.1327987766416.JavaMail.root@erie.cs.uoguelph.ca> In-Reply-To: <20120126082208.GA49394@icarus.home.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [172.17.91.202] X-Mailer: Zimbra 6.0.10_GA_2692 (ZimbraWebClient - FF3.0 (Win)/6.0.10_GA_2692) Cc: freebsd-fs@freebsd.org Subject: Re: Is doing mount -u -o udp useful for you on an NFS mount? 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: Tue, 31 Jan 2012 05:29:27 -0000 Jeremy Chadwick wrote: > On Wed, Jan 25, 2012 at 11:01:41PM -0500, Rick Macklem wrote: > > Using a "mount -u" to change from TCP to UDP for an > > NFS mount is somewhat broken for both NFS clients. > > To make it work correctly is not trivial. > > > > As such, I'd like to find out if anyone needs this > > capability? (Note, I am not talking about UDP mounts > > in general, just the case of switching a TCP mount to > > a UDP mount without doing an unmount/mount.) > > I've never seen any SAN admin do this, even on our production server > at > work (Solaris with a NetApp SAN). When it comes to NFS, the moral of > the story is always "reboot the machine" (which is good anyway, make > sure everything comes up on boot, else months from now you'll find out > the hard way). > > However, to squelch people from doing it, could mount_nfs(8) actually > be > modified to spit out a nastygram when someone attempts to do this, so > at > least the admin would know that such isn't supported due to the > extreme > complexities involved? > I've just committed a patch that sends a log warning message when someone does this. Thanks for the suggestion, rick