From mboxrd@z Thu Jan 1 00:00:00 1970 From: Riccardo Veraldi Subject: virtio disk and network performances Date: Wed, 29 Apr 2009 16:45:04 +0200 Message-ID: <49F867F0.2020909@cnaf.infn.it> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit To: kvm@vger.kernel.org Return-path: Received: from iris.cnaf.infn.it ([131.154.3.7]:59026 "EHLO iris.cnaf.infn.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752151AbZD2Opf (ORCPT ); Wed, 29 Apr 2009 10:45:35 -0400 Received: from darwin.cnaf.infn.it (darwin.cnaf.infn.it [131.154.3.242]) by iris.cnaf.infn.it (8.14.2/8.14.2) with ESMTP id n3TEkOgr005268 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 29 Apr 2009 16:46:25 +0200 Sender: kvm-owner@vger.kernel.org List-ID: Hello, I am little bit disappointed about virtio perormance. speaking about virtio disk performance I get about the same performances of non-virtio quests. I am using centos 5.3 2.6.18-128.1.6.el5 as host and the same centos 5.3 2.6.18-128.1.6.el5 as kvm guests with virtio backported to CentOS 5.2 kernel virtio_net 47169 0 virtio_blk 41417 3 virtio_pci 41921 0 virtio_ring 37441 1 virtio_pci virtio 39365 3 virtio_net,virtio_blk,virtio_pci Filesystem Size Used Avail Use% Mounted on /dev/mapper/VolGroup00-LogVol00 9.1G 1.5G 7.2G 17% / /dev/vda1 99M 19M 76M 20% /boot tmpfs 502M 0 502M 0% /dev/shm I use bonnie++ for I/O tests and I got closely the same results for virtio guests and non-virtio guests. Anyone experienced something different ? Speaking about virtio net performance I get good results but they are not symmetric. on a virtio guest I get ~1Gb/s inbound and ~600Mb/s outbound without virtio I get ~600Gb/s inbound and ~200MB/s outbound anyone has any idea how come hte performance is not symmetric ? thanks Rick