-<?xml version='1.0'?> <!--*-nxml-*-->
+<?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">
<!--
+ SPDX-License-Identifier: LGPL-2.1+
+
This file is part of systemd.
Copyright 2012 Lennart Poettering
<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>
<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
- randomly generated ID. See
+ <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>This tool will execute no operation if
- <filename>/etc/machine-id</filename> is already
- initialized.</para>
-
- <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>
-
- <para>If run inside a KVM virtual machine and a UUID is passed via
- the <option>-uuid</option> option, this UUID is used to initialize
- the machine ID instead of a randomly generated one. The caller
- must ensure that the UUID passed is sufficiently unique and is
- different for every booted instanced of the VM.</para>
-
- <para>Similar, if run inside a Linux container environment and a
- UUID is set 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>
+ <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 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="https://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>
<para>The following options are understood:</para>
<variablelist>
+
<varlistentry>
<term><option>--root=<replaceable>root</replaceable></option></term>
- <listitem><para>Takes a directory path as an argument. All
- paths will be prefixed with the given alternate
- <replaceable>root</replaceable> path, including config search
- paths. </para></listitem>
+ <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 committed 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>
<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>
projects / thirdparty / systemd.git / blobdiff