How to use the command 'systemd-detect-virt' (with examples)

This article will demonstrate several use cases of the ‘systemd-detect-virt’ command, which is used to detect execution in a virtualized environment. The command can detect various virtualization technologies, determine if it is running in a virtual machine or container, and can also check for hardware or container virtualization specifically.

Use case 1: List detectable virtualization technologies

Code:

systemd-detect-virt --list

Motivation: It can be useful to know which virtualization technologies are detectable by the system, especially when troubleshooting or working with specific virtualization software.

Explanation: The ‘–list’ option is used to list all the detectable virtualization technologies. This command will display a list of the supported virtualization technologies on the system.

Example output:

kvm
qemu
oracle
virtualbox
vmware

Use case 2: Detect virtualization and return status code

Code:

systemd-detect-virt

Motivation: Determining whether the system is running in a virtual machine or container can be valuable in certain situations, such as optimizing performance or identifying potential limitations.

Explanation: Running the ‘systemd-detect-virt’ command without any options will print the virtualization technology, if any, and return a zero status code if it is running in a VM or a container. If it is not running in a virtualized environment, the command will return a non-zero status code.

Example output:

qemu

Use case 3: Silent check without printing anything

Code:

systemd-detect-virt --quiet

Motivation: In some cases, it might be desirable to perform a virtualization check silently without printing any output. This can be useful when integrating the command into scripts or automation processes.

Explanation: The ‘–quiet’ option is used to suppress any output from the ‘systemd-detect-virt’ command. It will silently check for virtualization and return the appropriate status code without printing anything.

Example output: No output is generated.

Use case 4: Only detect container virtualization

Code:

systemd-detect-virt --container

Motivation: Differentiating between virtual machines and containers can be important when managing resources, security, or deploying applications. By detecting container virtualization, specific actions or configurations can be performed accordingly.

Explanation: The ‘–container’ option is used to detect container virtualization specifically. This command will print the virtualization technology, if any, and return a zero status code if it is running in a container. Otherwise, it will return a non-zero status code.

Example output:

lxc

Use case 5: Only detect hardware virtualization

Code:

systemd-detect-virt --vm

Motivation: Hardware virtualization allows running multiple operating systems or virtual machines on a single physical machine. Detecting hardware virtualization can be useful when setting up environments, installing software, or optimizing system performance.

Explanation: The ‘–vm’ option is used to detect hardware virtualization specifically. This command will print the virtualization technology, if any, and return a zero status code if it is running on hardware virtualization. Otherwise, it will return a non-zero status code.

Example output:

kvm

Conclusion:

The ‘systemd-detect-virt’ command provides useful functionality to detect virtualization technologies and determine if the system is running in a virtual machine or container. By utilizing the different options available, users can gather information about the virtualization environment, integrate the command into scripts, and perform specific actions based on the detected virtualization. Be sure to consult the command’s documentation for more information on its usage and additional options.