Date: Mon, 17 Oct 2005 12:29:59 -0700 From: Brooks Davis <brooks@one-eyed-alien.net> To: Jim Rees <rees@umich.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 Message-ID: <20051017192959.GB15097@odin.ac.hmc.edu> In-Reply-To: <20051014162122.8D1571BBDE@citi.umich.edu> References: <20051014162122.8D1571BBDE@citi.umich.edu>
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--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--
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