Enabling VNC on Existing KVM Instances

This article outlines the steps needed to enable VNC on existing virtual machines.

KVM

Step 1 - Shutdown the Instance

SSH into the host where the virtual machine of interest resides. To shut down the virtual machine gracefully, invoke the following command on the terminal:

virsh shutdown test-vm

where test-vm is the name of the virtual machine.

Check to see if the instance is in the shut off state by invoking the following:

virsh list --all

You may also SSH into the instance and power off the instance from the terminal.

If all else fails, you may want to shutdown the instance ungracefully.

virsh destroy test-vm

Step 2 - Edit the Virtual Machine's XML Configuration

After verifying that the instance is shut off, open the instance's XML configuration:

virsh edit test-vm

Add the following inside the <devices> element:

It should look similar to this:

<graphics type='vnc' port='-1' autoport='yes' listen='127.0.0.1' keymap='en-us'>

  <listen type='address' address='127.0.0.1'/>

  </graphics>

Step 3 - Start the Instance

Start the instance after saving the configuration:

virsh start test-vm

To verify whether the configuration succeeded, run the following on the terminal:

virsh vncdisplay test-vm

You should see something similar to this:

root@localhost:~# virsh vncdisplay test-vm

127.0.0.1:0