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A.5. Troubleshooting with Serial Consoles

Linux kernels can output information to serial ports. This is useful for debugging kernel panics and hardware issues with video devices or headless servers.
To enable serial console output for KVM guests:
  1. Ensure that the domain XML file of the guest includes configuration for the serial console. For example:
      <console type='pty'>
        <source path='/dev/pts/16'/>
        <target type='virtio' port='1'/>
        <alias name='console1'/>
  2. On the guest, follow the How can I enable serial console for Red Hat Enterprise Linux 7? article on Red Hat Knowledgebase.
On the host, you can then access the serial console with the following command, where guestname is the name of the guest virtual machine:
# virsh console guestname
You can also use virt-manager to display the virtual text console. In the guest console window, select Serial 1 in Text Consoles from the View menu.