A.12. KVM Networking Performance
Note
e1000
) driver is also supported as an emulated driver choice. To use the e1000
driver, replace virtio
in the procedure below with e1000
. For the best performance it is recommended to use the virtio
driver.
Procedure A.6. Switching to the virtio driver
- Shut down the guest operating system.
- Edit the guest's configuration file with the
virsh
command (whereGUEST
is the guest's name):#
virsh edit
GUEST
Thevirsh edit
command uses the$EDITOR
shell variable to determine which editor to use. - Find the network interface section of the configuration. This section resembles the snippet below:
<interface type='network'> [output truncated] <model type='rtl8139' /> </interface>
- Change the type attribute of the model element from
'rtl8139'
to'virtio'
. This will change the driver from the rtl8139 driver to the virtio driver.<interface type='network'> [output truncated] <model type=
'virtio'
/> </interface> - Save the changes and exit the text editor
- Restart the guest operating system.
Alternatively, new guests can be created with a different network driver. This may be required if you are having difficulty installing guests over a network connection. This method requires you to have at least one guest already created (possibly installed from CD or DVD) to use as a template.
- Create an XML template from an existing guest (in this example, named Guest1):
#
virsh dumpxml Guest1 > /tmp/guest-template.xml
- Copy and edit the XML file and update the unique fields: virtual machine name, UUID, disk image, MAC address, and any other unique parameters. Note that you can delete the UUID and MAC address lines and virsh will generate a UUID and MAC address.
#
cp /tmp/guest-template.xml /tmp/new-guest.xml
#vi /tmp/new-guest.xml
Add the model line in the network interface section:<interface type='network'> [output truncated] <model type='virtio' /> </interface>
- Create the new virtual machine:
#
virsh define /tmp/new-guest.xml
#virsh start new-guest