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



NAME         top

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

SYNOPSIS         top


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

        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:

           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 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

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

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

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

           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

COLOPHON         top

       This page is part of the systemd (systemd system and service manager)
       project.  Information about the project can be found at 
       ⟨⟩.  If you have a bug
       report for this manual page, see
       ⟨⟩.  This
       page was obtained from the project's upstream Git repository
       ⟨⟩ on 2020-08-13.  (At that
       time, the date of the most recent commit that was found in the repos‐
       itory was 2020-08-11.)  If you discover any rendering problems in
       this HTML version of the page, or you believe there is a better or
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       of the original manual page), send a mail to

systemd 246                                      SYSTEMD-MACHINE-ID-SETUP(1)

Pages that refer to this page: systemd-firstboot(1)systemd-firstboot.service(1)machine-id(5)30-systemd-environment-d-generator(7)lvmsystemid(7)systemd.directives(7)systemd.index(7)systemd-machine-id-commit.service(8)