From owner-freebsd-fs@FreeBSD.ORG Mon Oct 17 19:30:01 2005 Return-Path: X-Original-To: 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 04EAB16A422 for ; Mon, 17 Oct 2005 19:30:00 +0000 (GMT) (envelope-from brdavis@odin.ac.hmc.edu) Received: from odin.ac.hmc.edu (Odin.AC.HMC.Edu [134.173.32.75]) by mx1.FreeBSD.org (Postfix) with ESMTP id 9692B43D49 for ; Mon, 17 Oct 2005 19:30:00 +0000 (GMT) (envelope-from brdavis@odin.ac.hmc.edu) Received: from odin.ac.hmc.edu (localhost.localdomain [127.0.0.1]) by odin.ac.hmc.edu (8.13.0/8.13.0) with ESMTP id j9HJU0tJ007910; Mon, 17 Oct 2005 12:30:00 -0700 Received: (from brdavis@localhost) by odin.ac.hmc.edu (8.13.0/8.13.0/Submit) id j9HJTxSY007909; Mon, 17 Oct 2005 12:29:59 -0700 Date: Mon, 17 Oct 2005 12:29:59 -0700 From: Brooks Davis To: Jim Rees Message-ID: <20051017192959.GB15097@odin.ac.hmc.edu> References: <20051014162122.8D1571BBDE@citi.umich.edu> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="i9LlY+UWpKt15+FH" Content-Disposition: inline In-Reply-To: <20051014162122.8D1571BBDE@citi.umich.edu> User-Agent: Mutt/1.4.1i X-Virus-Scanned: by amavisd-new X-Spam-Status: No, hits=0.0 required=8.0 tests=none autolearn=no version=2.63 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on odin.ac.hmc.edu Cc: fs@freebsd.org, rick@snowhite.cis.uoguelph.ca 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 19:30:01 -0000 --i9LlY+UWpKt15+FH Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Oct 14, 2005 at 12:21:22PM -0400, Jim Rees wrote: > ps: It would be nice if someone with the right expertise could explore > other things in TCP specifically for NFS. For example, I don't see > why a retransmit timeout should go above about 100msec >=20 > nfs/rpc shouldn't retransmit at all over tcp except when there has been a > reconnect. Tcp might retransmit, but modern implementations will always > choose the right timeout dynamically, unless packet loss is excessive. That's not entierly true. I was talking to someone from Panasas last fall who was lamenting the lack of sub millisecond timeout support in the kernel because on a Gigabit Ethernet LAN, you can expect a response in less than 1ms and essentily all failures to respond in that time are caused by packet corruption or overflowing switch buffers. -- Brooks --=20 Any statement of the form "X is the one, true Y" is FALSE. PGP fingerprint 655D 519C 26A7 82E7 2529 9BF0 5D8E 8BE9 F238 1AD4 --i9LlY+UWpKt15+FH Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (GNU/Linux) iD8DBQFDU/u0XY6L6fI4GtQRAgxgAJ9gNr7vrvuAz7xTWgORz2BvxQCC3gCfX5fy 6J4tiVp3Oaqsib1+bDXGtD0= =sHox -----END PGP SIGNATURE----- --i9LlY+UWpKt15+FH--