SYSTEMD-MACHINE-ID-SETUP(1)				     systemd-machine-id-setup				       SYSTEMD-MACHINE-ID-SETUP(1)

NAME

       systemd-machine-id-setup - Initialize the machine ID in /etc/machine-id

SYNOPSIS

       systemd-machine-id-setup

DESCRIPTION

       systemd-machine-id-setup may be used by system installer tools to initialize the machine ID stored in /etc/machine-id at install time, with
       a provisioned or randomly generated ID. See machine-id(5) for more information about this file.

       If the tool is invoked without the --commit switch, /etc/machine-id is initialized with a valid, new machined ID if it is missing or empty.
       The new machine ID will be acquired in the following fashion:

	1. If a valid D-Bus machine ID is already configured for the system, the D-Bus machine ID is copied and used to initialize the machine ID
	   in /etc/machine-id.

	2. If run inside a KVM virtual machine and a UUID is configured (via the -uuid option), this UUID is used to initialize the machine ID.
	   The caller must ensure that the UUID passed is sufficiently unique and is different for every booted instance of the VM.

	3. Similarly, if run inside a Linux container environment and a UUID is configured for the container, this is used to initialize the
	   machine ID. For details, see the documentation of the Container Interface[1].

	4. Otherwise, a new ID is randomly generated.

       The --commit switch may be used to commit a transient machined ID to disk, making it persistent. For details, see below.

       Use systemd-firstboot(1) to initialize the machine ID on mounted (but not booted) system images.

OPTIONS

       The following options are understood:

       --root=root
	   Takes a directory path as argument. All paths operated will be prefixed with the given alternate root path, including the path for
	   /etc/machine-id itself.

       --commit
	   Commit a transient machine ID to disk. This command may be used to convert a transient machine ID into a persistent one. A transient
	   machine ID file is one that was bind mounted from a memory file system (usually "tmpfs") to /etc/machine-id during the early phase of
	   the boot process. This may happen because /etc is initially read-only and was missing a valid machine ID file at that point.

	   This command will execute no operation if /etc/machine-id is not mounted from a memory file system, or if /etc is read-only. The
	   command will write the current transient machine ID to disk and unmount the /etc/machine-id mount point in a race-free manner to ensure
	   that this file is always valid and accessible for other processes.

	   This command is primarily used by the systemd-machine-id-commit.service(8) early boot service.

       --print
	   Print the machine ID generated or committed after the operation is complete.

       -h, --help
	   Print a short help text and exit.

       --version
	   Print a short version string and exit.

EXIT STATUS

       On success, 0 is returned, a non-zero failure code otherwise.

SEE ALSO

       systemd(1), machine-id(5), systemd-machine-id-commit.service(8), dbus-uuidgen(1), systemd-firstboot(1)

NOTES

	1. Container Interface
	   https://www.freedesktop.org/wiki/Software/systemd/ContainerInterface

systemd 237													       SYSTEMD-MACHINE-ID-SETUP(1)