Return-Path: Received: from fieldses.org ([174.143.236.118]:50025 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752470Ab0LMTQo (ORCPT ); Mon, 13 Dec 2010 14:16:44 -0500 Date: Mon, 13 Dec 2010 14:16:35 -0500 To: Thomas Haynes Cc: DENIEL Philippe , linux-nfs@vger.kernel.org Subject: Re: Side effects of having NFSv4 mounted over udp Message-ID: <20101213191634.GB2230@fieldses.org> References: <4D05CF50.1010305@cea.fr> Content-Type: text/plain; charset=us-ascii In-Reply-To: From: "J. Bruce Fields" Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On Mon, Dec 13, 2010 at 01:04:28PM -0600, Thomas Haynes wrote: > > On Dec 13, 2010, at 1:46 AM, DENIEL Philippe wrote: > > > Hi, > > > > I know NFSv4 is definitely a connection oriented protocol, but noting prevent from using "mount -t nfs4 -o proto=udp <...>". Using TCP instead of UDP could be of great interest, especially in a HPC context where thousands of clients will operate at the same time. If a nfs mount point is made over udp, what would be the side effects ? I tried to run the connectathon on such a udp based mount point and I could find no errors. Is NFSv4/UDP a suitable solution ? Or does it make no sense to use udp ? > > > You might find that some implementations have UDP disabled and it might then make > it hard to triage what is going on. > > I believe both NetApp's OnTap and Oracle's Solaris have it turned off. The Linux server allows it, but I've been considering that a (low-priority) bug, so it wouldn't be safe to assume it will continue working. That aside, if you have a perfect network, NFSv4.0 at least will probably work. (Not 4.1 since backchannel setup will fail?) Are you really sure that you can't make tcp scale to thousands of clients? --b. > > > > > > Thanks in advance for your answer. > > > > Regards > > > > Philippe > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html