How to use the command virt-manager (with examples)

The virt-manager command is a CLI launcher for virt-manager, which is a desktop user interface for managing KVM and Xen virtual machines and LXC containers. It provides a convenient way to manage and control virtual machines and containers on Linux systems.

Use case 1: Launch virt-manager

Code:

virt-manager

Motivation: The virt-manager command without any additional arguments launches the virt-manager application. This use case is useful when you want to open the virt-manager interface to manage your virtual machines and containers.

Explanation: The command virt-manager launches the virt-manager application with its default settings.

Example output: The virt-manager user interface will open, allowing you to manage your virtual machines and containers.

Use case 2: Connect to a hypervisor

Code:

virt-manager --connect hypervisor_uri

Motivation: Sometimes, you may have multiple hypervisors or want to connect to a remote hypervisor. In such cases, you can use this command to explicitly specify the hypervisor URI to connect to.

Explanation: The --connect argument is used to specify the hypervisor URI to connect to. You need to replace hypervisor_uri with the actual URI of the hypervisor you want to connect to.

Example output: The virt-manager application will connect to the specified hypervisor URI and display the virtual machines and containers managed by that hypervisor.

Use case 3: Don’t fork virt-manager process into the background on startup

Code:

virt-manager --no-fork

Motivation: By default, when you launch virt-manager, it forks the process into the background. However, in some cases, you may want to keep the process in the foreground to easily monitor the output or debug any issues.

Explanation: The --no-fork argument is used to prevent virt-manager from forking into the background on startup. This keeps the virt-manager process running in the foreground.

Example output: The virt-manager application will launch and remain in the foreground, allowing you to monitor the output or debug any issues.

Use case 4: Print debug output

Code:

virt-manager --debug

Motivation: If you’re experiencing issues with the virt-manager application or want to troubleshoot any problems, enabling debug output can provide more detailed information about the processes and events happening within virt-manager.

Explanation: The --debug argument is used to enable debug output in virt-manager. This will print additional information about the application’s operations, which can be useful for troubleshooting purposes.

Example output: The virt-manager application will start and print debug information to the console or terminal, providing more detailed insights into its operations.

Use case 5: Open the “New VM” wizard

Code:

virt-manager --show-domain-creator

Motivation: When you want to create a new virtual machine, the “New VM” wizard in virt-manager guides you through the process, allowing you to specify the necessary configurations, such as the virtual machine type, storage, network, and other settings.

Explanation: The --show-domain-creator argument is used to open the “New VM” wizard in the virt-manager interface. This allows you to create a new virtual machine easily.

Example output: The “New VM” wizard will open in the virt-manager interface, providing options and fields to configure and create a new virtual machine.

Use case 6: Show domain details window

Code:

virt-manager --show-domain-editor name|id|uuid

Motivation: Sometimes, you may want to view or modify the details of a specific virtual machine. In such cases, you can use the --show-domain-editor argument to open the domain details window for the virtual machine specified by name, ID, or UUID.

Explanation: The --show-domain-editor argument is used to open the domain details window in the virt-manager interface. You need to replace name|id|uuid with the actual name, ID, or UUID of the virtual machine you want to view or modify.

Example output: The domain details window for the specified virtual machine will open in the virt-manager interface, displaying its configuration and allowing you to make changes if needed.

Use case 7: Show domain performance window

Code:

virt-manager --show-domain-performance name|id|uuid

Motivation: If you want to monitor the performance of a specific virtual machine, you can use the --show-domain-performance argument to open the domain performance window in the virt-manager interface. This window provides real-time performance metrics for the virtual machine.

Explanation: The --show-domain-performance argument is used to open the domain performance window in the virt-manager interface. You need to replace name|id|uuid with the actual name, ID, or UUID of the virtual machine you want to monitor.

Example output: The domain performance window for the specified virtual machine will open in the virt-manager interface, displaying real-time performance metrics such as CPU usage, memory usage, and network activity.

Use case 8: Show connection details window

Code:

virt-manager --show-host-summary

Motivation: The --show-host-summary argument is useful when you want to view the details of the connection to the hypervisor. It opens the connection details window in the virt-manager interface, providing information about the connected hypervisor.

Explanation: The --show-host-summary argument is used to open the connection details window in the virt-manager interface. This window displays information about the connected hypervisor, such as CPU model, memory, storage, and network details.

Example output: The connection details window for the connected hypervisor will open in the virt-manager interface, providing information about the hypervisor’s specifications and configurations.

Conclusion:

The virt-manager command is a powerful tool for managing and controlling virtual machines and containers through a desktop user interface. With various arguments available, it allows you to perform a wide range of actions, from launching the virt-manager application to creating or modifying virtual machines, monitoring performance, and viewing hypervisor details. By understanding how to use these different use cases, you can efficiently manage your virtualization environment.