From owner-freebsd-xen@FreeBSD.ORG Wed Mar 6 22:41:30 2013 Return-Path: Delivered-To: freebsd-xen@freebsd.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id 28BF7BDF for ; Wed, 6 Mar 2013 22:41:30 +0000 (UTC) (envelope-from bounces+73574-0602-freebsd-xen=freebsd.org@sendgrid.me) Received: from o3.shared.sendgrid.net (o3.shared.sendgrid.net [208.117.48.85]) by mx1.freebsd.org (Postfix) with SMTP id BBF85D8B for ; Wed, 6 Mar 2013 22:41:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sendgrid.info; h=from :mime-version:to:cc:subject:references:in-reply-to:content-type :content-transfer-encoding; s=smtpapi; bh=CsSxO3Y2wFaJaQXiwvZO5s P9i48=; b=wMBsNvMMGlkaYlNs8MMso6KsrCfkQmBF25igmReA4R+nfKGCHMHPV3 fnlKzdSo63cINZ+9h4d5VriRPVhVWj4N2h590Y+PnWj3pMNtUPIqsSEDacYjmukc 1++70fN+GeAVWZH+OHVHKcHa6N9hP8gB44EinEd+vviB6QpTCgPEw= Received: by 10.12.16.42 with SMTP id mf77.29463.5137C6178 Wed, 06 Mar 2013 16:41:27 -0600 (CST) Received: from mail.tarsnap.com (unknown [10.60.208.15]) by mi17 (SG) with ESMTP id 5137c617.6107.bef534 for ; Wed, 06 Mar 2013 16:41:27 -0600 (CST) Received: (qmail 16299 invoked from network); 6 Mar 2013 22:41:26 -0000 Received: from unknown (HELO clamshell.daemonology.net) (127.0.0.1) by ec2-107-20-205-189.compute-1.amazonaws.com with ESMTP; 6 Mar 2013 22:41:26 -0000 Received: (qmail 3117 invoked from network); 6 Mar 2013 22:40:38 -0000 Received: from unknown (HELO clamshell.daemonology.net) (127.0.0.1) by clamshell.daemonology.net with SMTP; 6 Mar 2013 22:40:38 -0000 Message-ID: <5137C5E6.2070802@freebsd.org> Date: Wed, 06 Mar 2013 14:40:38 -0800 From: Colin Percival User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:17.0) Gecko/20130131 Thunderbird/17.0.2 MIME-Version: 1.0 To: Jay West Subject: Re: misc. questions References: <000901ce1aa7$90704320$b150c960$@ezwind.net> In-Reply-To: <000901ce1aa7$90704320$b150c960$@ezwind.net> X-Enigmail-Version: 1.4.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Sendgrid-EID: RUbAm5H8PjswBj/QH+sYVehaJogg3iBnZcyVi1bw/Iyk0zImLtGyWkcNl/843m4YZPUzPxE6l/eh5fnFchOObhHMigd+QUc69nGFlDFN+EBqpwEzGrHPyGnGSRgQ4xHu Cc: freebsd-xen@freebsd.org X-BeenThere: freebsd-xen@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Discussion of the freebsd port to xen - implementation and usage List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 06 Mar 2013 22:41:30 -0000 On 03/06/13 12:17, Jay West wrote: > 1) One or two of our freebsd 9.1 HVM (with PVM drivers) under > Xenserver 6.1 advanced are fairly frequently generating this message on the > console: xn_txeof: WARNING: response is -1! Any ideas what this may be and > what should be done? It does seem to only occur on the machines that have > higher network load than the others. I see this on EC2 (running under HVM) as well. It doesn't seem to interfere with anything and only occurs occasionally (maybe five times per GB of network traffic?) so I haven't worried too much about it -- but if anyone has a clue about this I'd love to fix it from the "tidy up loose ends" perspective. > 2) We did a pilot project of about 8 VM's (the above mentioned > environment) and all went well. Now that we've moved it into production with > many more VM's, I'm wondering about recommended tuning. I seem to recall > from watching this list that there are a few sysctl's and the like that are > highly recommended, I think they had to do with network settings and turning > off "offloading" or somesuch. Does anyone have a quick & dirty list of > "here's the first things you should always change" with regards to FreeBSD > HVM (pvm drivers) under XenServer? You'll want to turn off tso, since it produces long mbuf chains which most xn netbacks choke on. (I have a very ugly workaround patch for this which I use on EC2, but simply turning off tso is enough unless you need Gbps+ speeds). There's a separate issue affecting pf+tso+xn (possibly pf+tso generally) which I haven't gotten around to tracking down. -- Colin Percival Security Officer Emeritus, FreeBSD | The power to serve Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid