From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Borntraeger Subject: Re: Network poblems using virtio and tap. Date: Sat, 6 Sep 2008 09:40:27 +0200 Message-ID: <200809060940.27765.borntraeger@de.ibm.com> References: <20080901124245.96790@gmx.net> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: "Fabian Deutsch" Return-path: Received: from mtagate3.de.ibm.com ([195.212.29.152]:64779 "EHLO mtagate3.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751959AbYIFHlZ (ORCPT ); Sat, 6 Sep 2008 03:41:25 -0400 Received: from d12nrmr1607.megacenter.de.ibm.com (d12nrmr1607.megacenter.de.ibm.com [9.149.167.49]) by mtagate3.de.ibm.com (8.13.8/8.13.8) with ESMTP id m867fKt5184824 for ; Sat, 6 Sep 2008 07:41:20 GMT Received: from d12av02.megacenter.de.ibm.com (d12av02.megacenter.de.ibm.com [9.149.165.228]) by d12nrmr1607.megacenter.de.ibm.com (8.13.8/8.13.8/NCO v9.1) with ESMTP id m867fEed3506398 for ; Sat, 6 Sep 2008 09:41:20 +0200 Received: from d12av02.megacenter.de.ibm.com (loopback [127.0.0.1]) by d12av02.megacenter.de.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m867fBta027299 for ; Sat, 6 Sep 2008 09:41:11 +0200 In-Reply-To: <20080901124245.96790@gmx.net> Content-Disposition: inline Sender: kvm-owner@vger.kernel.org List-ID: Am Montag, 1. September 2008 schrieb Fabian Deutsch: > Hey. > > I'm observing some network problems when using virtio and a tap if. > The trouble is a drop of network troughput from abot 90Mbit/s to about 90kbit/s, > after about 1.7 TB of transferred data. > > Setup > Host: > - Fedora 8, nearly all updates > - Intel(R) Xeon(R) CPU X3210 @ 2.13GHz > - 8GB RAM > - 2 Guests > > Guest: > - Fedora 9 all updates > - virtio nic using tap > - samba sharing a mountpoint using an iscsi target Can you tell us what host kernel and what guest kernel you are using? The were some changes to tun/tap for virtio lately which could make a difference. Christian