2012/12/3 Davide Guerri <d.guerri(a)unidata.it>
Hi,
I'm having some weird problem with the setup of the QoS on a bridged
network.
As the docs states, outbound/inbound average speed should be expressed in
KBps (KBytes per second) but in order to get a maximum speed of 10Mbps
(megabits per second) surprising enough I have to use 2560 on the guest
(not 1280 as expected).
Using 1280 units I get a speed og 5Mbps.
I'm aware of peak and burst parameters but even with them I'm seeing the
same (long-term) behavior.
Here follows my configuration.
Thank you in advance for any help you can provide.
Domain definition (relevant part only)
virsh # dumpxml mydomain
<domain type='kvm' id='45'>
[...]
<devices>
[...]
<interface type='network'>
<mac address='52:54:00:xx:xx:xx'/>
<source network='br909'/>
<target dev='vnet43'/>
<model type='virtio'/>
<bandwidth>
<inbound average='2560'/>
<outbound average='2560'/>
</bandwidth>
<alias name='net0'/>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x03'
function='0x0'/>
</interface>
[...]
</devices>
</domain>
The network definition:
virsh # net-dumpxml br909
<network>
<name>br909</name>
<uuid>07319380-2025-cdcc-924a-149cd0370b56</uuid>
<forward mode='bridge'/>
<bridge name='br909' />
</network>
And iperf result (client and server are on the same vlan and they are
running on the same host)
[ 5] local xx.xx.xx.xx port 5001 connected with xx.xx.xx.yy port 18396
[ 5] 0.0-30.1 sec 35.4 MBytes 9.87 Mbits/sec
provide your os version and libvirt version plz.
and use the following command to check the tc mtu size:
tc filter list dev vnet0 root
if the mtu size in the output is not 64kb,then you must update your libvirt
to 0.9.11 or later.