<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*--> <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> <!-- This file is part of systemd. Copyright 2012 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. --> <refentry id="systemd-machine-id-setup" xmlns:xi="http://www.w3.org/2001/XInclude"> <refentryinfo> <title>systemd-machine-id-setup</title> <productname>systemd</productname> <authorgroup> <author> <contrib>Developer</contrib> <firstname>Lennart</firstname> <surname>Poettering</surname> <email>lennart@poettering.net</email> </author> <author> <contrib>Developer</contrib> <firstname>Didier</firstname> <surname>Roche</surname> <email>didrocks@ubuntu.com</email> </author> </authorgroup> </refentryinfo> <refmeta> <refentrytitle>systemd-machine-id-setup</refentrytitle> <manvolnum>1</manvolnum> </refmeta> <refnamediv> <refname>systemd-machine-id-setup</refname> <refpurpose>Initialize the machine ID in /etc/machine-id</refpurpose> </refnamediv> <refsynopsisdiv> <cmdsynopsis> <command>systemd-machine-id-setup</command> </cmdsynopsis> </refsynopsisdiv> <refsect1> <title>Description</title> <para><command>systemd-machine-id-setup</command> may be used by system installer tools to initialize the machine ID stored in <filename>/etc/machine-id</filename> at install time, with a provisioned or randomly generated ID. See <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry> for more information about this file.</para> <para>If the tool is invoked without the <option>--commit</option> switch, <filename>/etc/machine-id</filename> 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:</para> <orderedlist> <listitem><para>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 <filename>/etc/machine-id</filename>.</para></listitem> <listitem><para>If run inside a KVM virtual machine and a UUID is was configured (via the <option>-uuid</option> 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.</para></listitem> <listitem><para>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 <ulink url="http://www.freedesktop.org/wiki/Software/systemd/ContainerInterface">Container Interface</ulink>.</para></listitem> <listitem><para>Otherwise, a new ID is randomly generated.</para></listitem> </orderedlist> <para>The <option>--commit</option> switch may be used to commit a transient machined ID to disk, making it persistent. For details, see below.</para> <para>Use <citerefentry><refentrytitle>systemd-firstboot</refentrytitle><manvolnum>1</manvolnum></citerefentry> to initialize the machine ID on mounted (but not booted) system images.</para> </refsect1> <refsect1> <title>Options</title> <para>The following options are understood:</para> <variablelist> <varlistentry> <term><option>--root=<replaceable>root</replaceable></option></term> <listitem><para>Takes a directory path as argument. All paths operated will be prefixed with the given alternate <replaceable>root</replaceable> path, including the path for <filename>/etc/machine-id</filename> itself.</para></listitem> </varlistentry> <varlistentry> <term><option>--commit</option></term> <listitem><para>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 <literal>tmpfs</literal>) to <filename>/etc/machine-id</filename> during the early phase of the boot process. This may happen because <filename>/etc</filename> is initially read-only and was missing a valid machine ID file at that point.</para> <para>This command will execute no operation if <filename>/etc/machine-id</filename> is not mounted from a memory file system, or if <filename>/etc</filename> is read-only. The command will write the current transient machine ID to disk and unmount the <filename>/etc/machine-id</filename> mount point in a race-free manner to ensure that this file is always valid and accessible for other processes.</para> <para>This command is primarily used by the <citerefentry><refentrytitle>systemd-machine-id-commit.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> early boot service.</para></listitem> </varlistentry> <varlistentry> <term><option>--print</option></term> <listitem><para>Print the machine ID generated or commited after the operation is complete.</para></listitem> </varlistentry> <xi:include href="standard-options.xml" xpointer="help" /> <xi:include href="standard-options.xml" xpointer="version" /> </variablelist> </refsect1> <refsect1> <title>Exit status</title> <para>On success, 0 is returned, a non-zero failure code otherwise.</para> </refsect1> <refsect1> <title>See Also</title> <para> <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd-machine-id-commit.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry project='dbus'><refentrytitle>dbus-uuidgen</refentrytitle><manvolnum>1</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd-firstboot</refentrytitle><manvolnum>1</manvolnum></citerefentry> </para> </refsect1> </refentry>