[libvirt-users] Strange results with QoS definition

Hi I'm currenty testing network QoS implementations stumbled upon quite strange results when using QoS definitions inside the virtdomain xml. I'm testing bandwidth from a virtdomain towards a hardware server connected to the same switch, both connected to gigabit ports. Iperf tells me the bandwidth is around 939 Mbit/s. I added this to my virtdomains xml: <bandwidth> <inbound average='1280'/> <outbound average='1280'/> </bandwidth> This should limit the bandwidth to around 10 megabit/s 1280 kilobytes/s, however i get only around 5.14 Mbits/sec... Has anyone an idea what causes this difference? I already checked the applied qdisc & class: root@testvirt-patrick:~ # tc qdisc sh dev vnet1 qdisc htb 1: root refcnt 2 r2q 10 default 1 direct_packets_stat 0 qdisc ingress ffff: parent ffff:fff1 ---------------- root@testvirt-patrick:~ # tc class sh dev vnet1 class htb 1:1 root prio 0 rate 10240Kbit ceil 10240Kbit burst 1598b cburst 1598b Freundliche Grüsse / kind regards Patrick Herzfeld -- Nine Internet Solutions AG, Albisriederstrasse 243a, CH-8047 Zuerich Tel +41 44 637 40 00 | Support +41 44 637 40 40 | Fax +41 44 637 40 01