B.5. Internal error cannot find character device (null)

Symptom
This error message appears when attempting to connect to a guest virtual machine's console: 
# virsh console test2 Connected to domain test2 Escape character is ^] error: internal error cannot find character device (null)
Investigation
This error message shows that there is no serial console configured for the guest virtual machine.
Solution
Set up a serial console in the guest's XML file.

Procedure B.1. Setting up a serial console in the guest's XML

  1. Add the following XML to the guest virtual machine's XML using virsh edit: 
    <serial type='pty'>
  <target port='0'/>
</serial>
<console type='pty'>
  <target type='serial' port='0'/>
</console>
  2. Set up the console in the guest kernel command line.
    To do this, either log in to the guest virtual machine to edit the /boot/grub/grub.conf file directly, or use the virt-edit command line tool. Add the following to the guest kernel command line: 
    console=ttyS0,115200
  3. Run the followings command: 
    # virsh start vm && virsh console vm