From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: Networking performance on a KVM Host (with no guests) Date: Thu, 19 Apr 2012 08:43:06 +0300 Message-ID: <20120419054306.GV11918@redhat.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org To: Chegu Vinod Return-path: Received: from mx1.redhat.com ([209.132.183.28]:3782 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751143Ab2DSFnU (ORCPT ); Thu, 19 Apr 2012 01:43:20 -0400 Content-Disposition: inline In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On Thu, Apr 19, 2012 at 03:53:39AM +0000, Chegu Vinod wrote: > > Hello, > > Perhaps this query was answered in the past. If yes kindly point me to > the same. > > We noticed differences in networking performance (measured via netperf > over a 10G NIC) on an X86_64 server between the following two > configurations : > > 1) Server run as a KVM Host (but with no KVM guests created on it (or) no > extra bridges created other than the default vibr0 bridge) > > vs. > > 2) The same server running the same version of Linux but without any of the > virtualization software installed on it. > > Config #2 performed much better ! > Is this expected ? What are the reasons behind this ? > > Is there any way to gain back the loss in performance on the KVM host > without having to uninstall the virtualization software (i.e. in Config 1). > Can you list exactly what you need to uninstall to get performance back? -- Gleb.