systemd-machine-id-setup

SYSTEMD-MACHINE-ID-SETUP(1)systemd-machine-id-setupSYSTEMD-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://systemd.io/CONTAINER_INTERFACE

systemd 245                                        SYSTEMD-MACHINE-ID-SETUP(1)