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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
       http://www.freedesktop.org/wiki/Software/systemd/ContainerInterface



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