How to use the command `systemd-sysext` (with examples)

The systemd-sysext command is used to activate or deactivate system extension images. Systemd is a system and service manager for Linux operating systems. This command provides functionality to manage system extensions. It can be used to list installed extension images, merge extension images into specific directories, check the merge status, unmerge extension images, and refresh extension images.

Use case 1: List installed extension images

Code:

systemd-sysext list

Motivation: By listing the installed extension images, we can quickly check which extensions are currently present on the system. This information can be useful for troubleshooting or verifying the installation of specific extensions.

Explanation: This command simply lists all the installed extension images on the system.

Example output:

ext-image-1
ext-image-2
ext-image-3

Use case 2: Merge system extension images into /usr/ and /opt/

Code:

systemd-sysext merge

Motivation: Merging system extension images into specific directories allows the extensions to be activated and used. This is useful when you have installed new extensions and want to make them accessible system-wide.

Explanation: The merge subcommand of systemd-sysext is used to merge the installed extension images into the /usr/ and /opt/ directories. Once merged, the extensions will be available for use.

Example output:

Merging extension images...
Extension images merged successfully.

Use case 3: Check the current merge status

Code:

systemd-sysext status

Motivation: Checking the merge status can help determine whether the system extension images have been successfully merged. This information is helpful for verifying the installation or troubleshooting any potential issues.

Explanation: This command provides information about the current merge status of the system extension images.

Example output:

Merge status:
- ext-image-1: Merged
- ext-image-2: Not merged
- ext-image-3: Merged

Use case 4: Unmerge all currently installed system extension images

Code:

systemd-sysext unmerge

Motivation: Unmerging installed system extension images allows them to be deactivated and removed from the system. This is useful when you no longer need certain extensions and want to free up resources.

Explanation: The unmerge subcommand of systemd-sysext is used to unmerge all currently installed system extension images from the /usr/ and /opt/ directories. This operation deactivates the extensions and removes them from the system.

Example output:

Unmerging extension images...
Extension images unmerged successfully.

Use case 5: Refresh system extension images

Code:

systemd-sysext refresh

Motivation: Refreshing the system extension images allows you to update them or apply any changes made to the images. This is useful when you have modified the extension images and want to ensure the changes are applied.

Explanation: The refresh subcommand of systemd-sysext combines the unmerge and merge operations. It unmerges the currently installed system extension images and then merges them again into the specified directories (/usr/ and /opt/). This process refreshes the extension images.

Example output:

Unmerging extension images...
Extension images unmerged successfully.

Merging extension images...
Extension images merged successfully.

Conclusion:

The systemd-sysext command provides a set of useful functionalities for managing system extension images. By listing, merging, checking the merge status, unmerging, and refreshing these images, users can control the availability and activation of system extensions on their Linux systems.