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Diffstat (limited to 'man/machine-id.xml')
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diff --git a/man/machine-id.xml b/man/machine-id.xml deleted file mode 100644 index d318ec54ec..0000000000 --- a/man/machine-id.xml +++ /dev/null @@ -1,146 +0,0 @@ -<?xml version='1.0'?> <!--*-nxml-*--> -<!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 2010 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="machine-id"> - <refentryinfo> - <title>machine-id</title> - <productname>systemd</productname> - - <authorgroup> - <author> - <contrib>Developer</contrib> - <firstname>Lennart</firstname> - <surname>Poettering</surname> - <email>lennart@poettering.net</email> - </author> - </authorgroup> - </refentryinfo> - - <refmeta> - <refentrytitle>machine-id</refentrytitle> - <manvolnum>5</manvolnum> - </refmeta> - - <refnamediv> - <refname>machine-id</refname> - <refpurpose>Local machine ID configuration file</refpurpose> - </refnamediv> - - <refsynopsisdiv> - <para><filename>/etc/machine-id</filename></para> - </refsynopsisdiv> - - <refsect1> - <title>Description</title> - - <para>The <filename>/etc/machine-id</filename> file contains the - unique machine ID of the local system that is set during - installation. The machine ID is a single newline-terminated, - hexadecimal, 32-character, lowercase machine ID string. When - decoded from hexadecimal, this corresponds with a 16-byte/128-bit - string.</para> - - <para>The machine ID is usually generated from a random source - during system installation and stays constant for all subsequent - boots. Optionally, for stateless systems, it is generated during - runtime at early boot if it is found to be empty.</para> - - <para>The machine ID does not change based on user configuration - or when hardware is replaced.</para> - - <para>This machine ID adheres to the same format and logic as the - D-Bus machine ID.</para> - - <para>Programs may use this ID to identify the host with a - globally unique ID in the network, which does not change even if - the local network configuration changes. Due to this and its - greater length, it is a more useful replacement for the - <citerefentry project='man-pages'><refentrytitle>gethostid</refentrytitle><manvolnum>3</manvolnum></citerefentry> - call that POSIX specifies.</para> - - <para>The - <citerefentry><refentrytitle>systemd-machine-id-setup</refentrytitle><manvolnum>1</manvolnum></citerefentry> - tool may be used by installer tools to initialize the machine ID - at install time. Use - <citerefentry><refentrytitle>systemd-firstboot</refentrytitle><manvolnum>1</manvolnum></citerefentry> - to initialize it on mounted (but not booted) system images.</para> - - <para>The machine-id may also be set, for example when network - booting, by setting the <varname>systemd.machine_id=</varname> - kernel command line parameter or passing the option - <option>--machine-id=</option> to systemd. A machine-id may not - be set to all zeros.</para> - </refsect1> - - <refsect1> - <title>Relation to OSF UUIDs</title> - - <para>Note that the machine ID historically is not an OSF UUID as - defined by <ulink url="https://tools.ietf.org/html/rfc4122">RFC - 4122</ulink>, nor a Microsoft GUID; however, starting with systemd - v30, newly generated machine IDs do qualify as v4 UUIDs.</para> - - <para>In order to maintain compatibility with existing - installations, an application requiring a UUID should decode the - machine ID, and then apply the following operations to turn it - into a valid OSF v4 UUID. With <literal>id</literal> being an - unsigned character array:</para> - - <programlisting>/* Set UUID version to 4 --- truly random generation */ -id[6] = (id[6] & 0x0F) | 0x40; -/* Set the UUID variant to DCE */ -id[8] = (id[8] & 0x3F) | 0x80;</programlisting> - - <para>(This code is inspired by - <literal>generate_random_uuid()</literal> of - <filename>drivers/char/random.c</filename> from the Linux kernel - sources.)</para> - - </refsect1> - - <refsect1> - <title>History</title> - - <para>The simple configuration file format of - <filename>/etc/machine-id</filename> originates in the - <filename>/var/lib/dbus/machine-id</filename> file introduced by - D-Bus. In fact, this latter file might be a symlink to - <filename>/etc/machine-id</filename>.</para> - </refsect1> - - <refsect1> - <title>See Also</title> - <para> - <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, - <citerefentry><refentrytitle>systemd-machine-id-setup</refentrytitle><manvolnum>1</manvolnum></citerefentry>, - <citerefentry project='man-pages'><refentrytitle>gethostid</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>hostname</refentrytitle><manvolnum>5</manvolnum></citerefentry>, - <citerefentry><refentrytitle>machine-info</refentrytitle><manvolnum>5</manvolnum></citerefentry>, - <citerefentry><refentrytitle>os-release</refentrytitle><manvolnum>5</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd-id128</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_id128_get_machine</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>systemd-firstboot</refentrytitle><manvolnum>1</manvolnum></citerefentry> - </para> - </refsect1> - -</refentry> |