systemd-machine-id-setup(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXIT STATUS | SEE ALSO | NOTES | COLOPHON

SYSTEMD-MACHINE-ID-SETUP(1)temd-machine-id-setupTEMD-MACHINE-ID-SETUP(1)

NAME         top

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

SYNOPSIS         top

       systemd-machine-id-setup

DESCRIPTION         top

       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         top

       The following options are understood:

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

       --image=path
           Takes a path to a device node or refular file as argument.
           This is similar to --root= as described above, but operates
           on a disk image instead of a directory tree.

       --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         top

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

SEE ALSO         top

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

NOTES         top

        1. Container Interface
           https://systemd.io/CONTAINER_INTERFACE

COLOPHON         top

       This page is part of the systemd (systemd system and service
       manager) project.  Information about the project can be found at
       ⟨http://www.freedesktop.org/wiki/Software/systemd⟩.  If you have
       a bug report for this manual page, see
       ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.
       This page was obtained from the project's upstream Git repository
       ⟨https://github.com/systemd/systemd.git⟩ on 2021-04-01.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2021-04-01.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

systemd 248                                  SYSTEMD-MACHINE-ID-SETUP(1)

Pages that refer to this page: systemd-firstboot(1)machine-id(5)lvmsystemid(7)systemd.directives(7)systemd.index(7)systemd-machine-id-commit.service(8)