From owner-freebsd-current@FreeBSD.ORG Thu Nov 18 00:02:12 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id EECF316A4CE; Thu, 18 Nov 2004 00:02:12 +0000 (GMT) Received: from pi.codefab.com (pi.codefab.com [199.103.21.227]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7F35943D41; Thu, 18 Nov 2004 00:02:12 +0000 (GMT) (envelope-from cswiger@mac.com) Received: from [192.168.1.250] (pool-68-161-115-118.ny325.east.verizon.net [68.161.115.118]) by pi.codefab.com (8.12.11/8.12.11) with ESMTP id iAI01jaw065246 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 17 Nov 2004 19:01:57 -0500 (EST) Message-ID: <419BE654.6020705@mac.com> Date: Wed, 17 Nov 2004 19:01:24 -0500 From: Chuck Swiger Organization: The Courts of Chaos User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.3) Gecko/20040910 X-Accept-Language: en-us, en MIME-Version: 1.0 Followup-To: freebsd-current@freebsd.org To: Emanuel Strobl References: <200411172357.47735.Emanuel.Strobl@gmx.net> In-Reply-To: <200411172357.47735.Emanuel.Strobl@gmx.net> X-Enigmail-Version: 0.86.1.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, hits=-4.3 required=5.5 tests=AWL,BAYES_00 autolearn=ham version=2.64 X-Spam-Checker-Version: SpamAssassin 2.64 (2004-01-11) on pi.codefab.com cc: freebsd-current@freebsd.org cc: freebsd-stable@freebsd.org Subject: Re: serious networking (em) performance (ggate and NFS) problem X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 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: Thu, 18 Nov 2004 00:02:13 -0000 Emanuel Strobl wrote: [ ... ] > Tests were done with two Intel GigaBit Ethernet cards (82547EI, 32bit PCI > Desktop adapter MT) connected directly without a switch/hub If filesharing via NFS is your primary goal, it's reasonable to test that, however it would be easier to make sense of your results by testing your network hardware at a lower level. Since you're already running portmap/RPC, consider using spray to blast some packets rapidly and see what kind of bandwidth you max out using that. Or use ping with -i & -s set to reasonable values depending on whether you're using jumbo frames or not. If the problem is your connection is dropping a few packets, this will show up better here. Using "ping -f" is also a pretty good troubleshooter. If you can dig up a gigabit switch with management capabilities to test with, taking a look at the per-port statistics for errors would also be worth doing. A dodgy network cable can still work well enough for the cards to have a green link light, but fail to handle high traffic properly. [ ... ] > - em seems to have problems with MTU greater than 1500 Have you tried using an MTU of 3K or 7K? I also seem to recall that there were performance problems with em in 5.3 and a fix is being tested in -CURRENT. [I just saw Scott's response to the list, and your answer, so maybe nevermind this point.] > - UDP seems to have performance disadvantages over TCP regarding NFS which > should be vice versa AFAIK Hmm, yeah...again, this makes me wonder whether you are dropping packets. NFS over TCP does better than UDP does in lossy network conditions. > - polling and em (GbE) with HZ=256 is definitly no good idea, even 10Base-2 > can compete You should be setting HZ to 1000, 2000, or so when using polling, and a higher HZ is definitely recommmended when you add in jumbo frames and GB speeds. -- -Chuck PS: followup-to set to reduce crossposting...