Connect to KVM: virsh Serial Console

Connect to KVM: `virsh` Serial Console

You can access a KVM instance directly using a serial console interface.

The following information describes how to establish a serial console connection to a KVM instance by using the virsh console command.

Note:

A serial console connection to a KVM instance might be useful when a the instance isn't configured with a GUI display, or if the instance lacks a network configuration, preventing SSH access.

What Do you Need?

Administrator privileges
Name of the KVM instance.
The KVM instance is configured for serial console use. For example:
- KVM serial console device defined – Ensure that a serial console device is defined on KVM. For example:
```
sudo virsh ttyconsole kvm_name
```
  If output is shown, a serial console device is defined. Otherwise, define a serial console in the KVM XML configuration. One method you can use is virsh edit. For example, run:
```
sudo virsh edit
```
  Within the <devices> tag, add the following text to the XML. For example:
```
<devices>
  <console type='pty'/>
</devices>
```
  See Domain XML format for more information.
- KVM kernel console option enabled – Ensure that console=ttyS0 kernel option is enabled on KVM. If this option isn't configured, the virsh console connection to the serial console will be unresponsive.
  To verify the console=ttyS0 kernel option is configured on the KVM, use the cat /proc/cmdline command. The output configuration must include console=[console-name]. If the output doesn't include a console configuration, you must enable the console=ttyS0 kernel option.
  To enable the console=ttyS0 kernel option, (1) type:
```
sudo grubby --update-kernel=ALL --args="console=ttyS0"
```
  (2) Ensure that the changes were applied, type:
```
sudo grub2-editenv - unset kernelopts
```
  (3) Reboot the KVM instance.

Steps

Follow these steps to directly connect to the KVM serial console.

On the host system, use the virsh console command to open up a KVM session in a serial console. For example:
```
sudo virsh console testguest
```
Where testguest is the name of the KVM guest.
You can interact with the virsh serial console in the same way as you would with the CLI.

Note:
If the connection failed and the guest serial console is unresponsive, you can exit the connection by pressing: Ctrl key and the ] right square bracket key.