From mboxrd@z Thu Jan 1 00:00:00 1970 From: Fabian Deutsch Subject: massive performance drop after a while when using virtio nics Date: Sat, 23 Aug 2008 21:21:56 +0200 Message-ID: <1219519317.2909.12.camel@decade.local> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit To: kvm@vger.kernel.org Return-path: Received: from mail.gmx.net ([213.165.64.20]:59815 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753181AbYHWTWA (ORCPT ); Sat, 23 Aug 2008 15:22:00 -0400 Sender: kvm-owner@vger.kernel.org List-ID: Hey. When running a guest in the following setup, I observ a "massive" performance decrease after a couple of gigabytes of transfrerred data. other guests keep running fine (no regressions) and nothing unusual is observed on the host. fedora 8 host, kvm-72 (user and module) fedora 9 guest, all updates. nic 0, vtio: subnet a samba listening nic 1, vtio: subnet b iscsi initiator running samba shares a mount point, pointing to an iscsi target. now pulling/pushing about 80GB over samba results in a drop from about 60/70Mbit to about 1/2Mbit of troughput. The problem is reproducible. The problem is solved after a reboot of the guest. Just restarting networking doesn't help. Guest's dmesg doesn't say anything about problems. No errors in ifconfig. Has someone observed something similar? Greetings - fabian