On Tue, Aug 3, 2010 at 11:04 PM, Nirmal Guhan <vavatutu@xxxxxxxxx> wrote: > I am seeing a performance degradation while using libvirt to start my > vm (kvm). vm is fedora 12 and host is also fedora 12, both with > 2.6.32.10-90.fc12.i686. Here are the statistics from iperf : > > From VM: [ 3] 0.0-30.0 sec 199 MBytes 55.7 Mbits/sec [...] > qemu kvm : [ 3] 0.0-30.0 sec 329 MBytes 91.9 Mbits/sec Is this what you are comparing: 91.9 -> 55.7 Mbits/s? > Command used : qemu-kvm vdisk.img -m 512 -net nic,model=virtio > macaddr=$macaddress -net tap,script=/etc/qemu-ifup Have you tried to bisect the command-lines by dropping options from the libvirt command-line until you arrive at the manual qemu-kvm command-line? Try using your own tap networking instead of libvirt's but otherwise keeping libvirt's command-line as much as possible. Can you use /var/lib/libvirt/f12.img with the manual qemu-kvm instead of the vdisk.img file? In general, try to compare same with same and eliminate variables. Stefan -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
