lfs-book/chapter06/systemd.xml

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  <!ENTITY % general-entities SYSTEM "../general.ent">
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<sect1 id="ch-system-systemd" role="wrap">
  <?dbhtml filename="systemd.html"?>

  <sect1info condition="script">
    <productname>systemd</productname>
    <productnumber>&systemd-version;</productnumber>
    <address>&systemd-url;</address>
  </sect1info>

  <title>Systemd-&systemd-version;</title>

  <indexterm zone="ch-system-systemd">
    <primary sortas="a-Systemd">Systemd</primary>
  </indexterm>

  <sect2 role="package">
    <title/>

    <para>The Systemd package contains programs for controlling the startup,
    running, and shutdown of the system.</para>

    <segmentedlist>
      <segtitle>&buildtime;</segtitle>
      <segtitle>&diskspace;</segtitle>

      <seglistitem>
        <seg>&systemd-ch6-sbu;</seg>
        <seg>&systemd-ch6-du;</seg>
      </seglistitem>
    </segmentedlist>
  </sect2>

  <sect2 role="installation">
    <title>Installation of Systemd</title>

    <para>Prepare Systemd for compilation:</para>

<screen><userinput remap="configure">./configure --prefix=/usr \
            --sysconfdir=/etc \
            --localstatedir=/var \
            --libexecdir=/usr/lib \
            --docdir=/usr/share/doc/systemd-&systemd-version; \
            --with-rootprefix= \
            --with-rootlibdir=/lib \
            --with-kbd-loadkeys=/bin/loadkeys \
            --with-kbd-setfont=/bin/setfont \
            --enable-split-usr \
            --disable-gudev \
            --without-python</userinput></screen>

    <variablelist>
      <title>The meaning of the configure options:</title>

      <varlistentry>
        <term><parameter>--with-root*</parameter></term>
        <listitem>
          <para>These switches ensure that core programs and
          shared libraries are installed in the subdirectories
          of the root partition.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><parameter>--with-kbd-*</parameter></term>
        <listitem>
          <para>These switches tell Systemd where to find
          Kbd programs.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><parameter>--enable-split-usr</parameter></term>
        <listitem>
          <para>This switch ensures that Systemd will work on
          systems where /bin, /lib and /sbin directories are not
          symlinks to their /usr counterparts.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><parameter>--disable-gudev --without-python</parameter></term>
        <listitem>
          <para>These switches disable optional features because
          LFS does not provide their dependencies.</para>
        </listitem>
      </varlistentry>

    </variablelist>

    <para>Compile the package:</para>

<screen><userinput remap="make">make</userinput></screen>

    <para>The package comes with a testsuite, but it doesn't work in
    chroot. It needs to be run from a system booted using Systemd.</para>

    <para>Install the package:</para>

<screen><userinput remap="install">make install</userinput></screen>

    <para>Create the Sysvinit compatibility symlinks, so Systemd is used
    as the default init system:</para>

<screen><userinput remap="install">for tool in runlevel reboot shutdown poweroff halt telinit; do
     ln -sfv ../bin/systemctl /sbin/$tool
done
ln -sfv ../lib/systemd/systemd /sbin/init</userinput></screen>

    <para>By default, Journald logs to a tmpfs which means that logs
    are not persistent through reboots. To make it log to a disk,
    create the <filename class="directory">
    /var/log/journal</filename> directory:</para>

<screen><userinput remap="install">mkdir -pv /var/log/journal</userinput></screen>

    <para>Remove a reference to a non-existent group:</para>

<screen><userinput remap="install">sed -i "s@0775 root lock@0755 root root@g" /usr/lib/tmpfiles.d/legacy.conf</userinput></screen>

    <para>Create the <filename>/etc/machine-id</filename> file needed by
    Journald:</para>

<screen><userinput>systemd-machine-id-setup</userinput></screen>

  </sect2>

  <sect2 id="contents-systemd" role="content">
    <title>Contents of Systemd</title>

    <segmentedlist>
      <segtitle>Installed programs</segtitle>
      <segtitle>Installed libraries</segtitle>
      <segtitle>Installed directories</segtitle>

      <seglistitem>
        <seg>halt, hostnamectl, init, journalctl, localectl, loginctl,
        poweroff, reboot, runlevel, shutdown, systemctl, systemd-analyze,
        systemd-ask-password, systemd-cat, systemd-cgls, systemd-cgtop,
        systemd-coredumpctl, systemd-delta, systemd-detect-virt,
        systemd-inhibit, systemd-machine-id-setup, systemd-notify,
        systemd-nspawn, systemd-stdio-bridge, systemd-tmpfiles,
        systemd-tty-ask-password-agent, telinit, timedatectl and
        udevadm</seg>
        <seg>libnss_myhostname.so.2, libsystemd-daemon.so, libsystemd-id128.so,
        libsystemd-journal.so, libsystemd-login.so and libudev.so</seg>
        <seg>/etc/binfmt.d, /etc/init.d, /etc/modules-load.d, /etc/rpm,
        /etc/sysctl.d, /etc/systemd, /etc/tmpfiles.d, /etc/udev,
        /etc/xdg/systemd, /lib/systemd, /lib/udev, /usr/include/systemd,
        /usr/lib/binfmt.d, /usr/lib/modules-load.d, /usr/lib/sysctl.d,
        /usr/lib/systemd, /usr/lib/tmpfiles.d, /usr/share/doc/systemd-&systemd-version;,
        /usr/share/systemd, /var/lib/systemd and /var/log/journald</seg>
      </seglistitem>
    </segmentedlist>

    <variablelist>
      <bridgehead renderas="sect3">Short Descriptions</bridgehead>
      <?dbfo list-presentation="list"?>
      <?dbhtml list-presentation="table"?>

      <varlistentry id="halt">
        <term><command>halt</command></term>
        <listitem>
          <para>Normally invokes <command>shutdown</command> with the
          <parameter>-h</parameter> option, except when already in run-level 0,
          then it tells the kernel to halt the system; it notes in the
          file <filename>/var/log/wtmp</filename> that the system is being
          brought down.</para>
          <indexterm zone="ch-system-systemd halt">
            <primary sortas="b-halt">halt</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="hostnamectl">
        <term><command>hostnamectl</command></term>
        <listitem>
          <para>used to query and change the system hostname and related
          settings.</para>
          <indexterm zone="ch-system-systemd hostnamectl">
            <primary sortas="b-hostnamectl">hostnamectl</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="init">
        <term><command>init</command></term>
        <listitem>
          <para>The first process to be started when the kernel has initialized
          the hardware which takes over the boot process and starts all the
          proceses it is instructed to.</para>
          <indexterm zone="ch-system-systemd init">
            <primary sortas="b-init">init</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="journalctl">
        <term><command>journalctl</command></term>
        <listitem>
          <para>used to query the contents of the Systemd Journal.</para>
          <indexterm zone="ch-system-systemd journalctl">
            <primary sortas="b-journalctl">journalctl</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="localectl">
        <term><command>localectl</command></term>
        <listitem>
          <para>used to query and change the system locale and keyboard layout
          settings.</para>
          <indexterm zone="ch-system-systemd localectl">
            <primary sortas="b-localectl">localectl</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="loginctl">
        <term><command>loginctl</command></term>
        <listitem>
          <para>used to introspect and control the state of the Systemd Login
          Manager.</para>
          <indexterm zone="ch-system-systemd loginctl">
            <primary sortas="b-loginctl">loginctl</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="poweroff">
        <term><command>poweroff</command></term>
        <listitem>
          <para>Tells the kernel to halt the system and switch off the computer
          (see <command>halt</command>).</para>
          <indexterm zone="ch-system-systemd poweroff">
            <primary sortas="b-poweroff">poweroff</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="reboot">
        <term><command>reboot</command></term>
        <listitem>
          <para>Tells the kernel to reboot the system (see
          <command>halt</command>).</para>
          <indexterm zone="ch-system-systemd reboot">
            <primary sortas="b-reboot">reboot</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="runlevel">
        <term><command>runlevel</command></term>
        <listitem>
          <para>Reports the previous and the current run-level, as noted in the
          last run-level record in <filename>/var/run/utmp</filename>.</para>
          <indexterm zone="ch-system-systemd runlevel">
            <primary sortas="b-runlevel">runlevel</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="shutdown">
        <term><command>shutdown</command></term>
        <listitem>
          <para>Brings the system down in a secure way, signaling all processes
          and notifying all logged-in users.</para>
          <indexterm zone="ch-system-systemd shutdown">
            <primary sortas="b-shutdown">shutdown</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="systemctl">
        <term><command>systemctl</command></term>
        <listitem>
          <para>used to introspect and control the state of the Systemd system and
          service manager.</para>
          <indexterm zone="ch-system-systemd systemctl">
            <primary sortas="b-systemctl">systemctl</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="systemd-analyze">
        <term><command>systemd-analyze</command></term>
        <listitem>
          <para>used to determine system boot-up performance of the current boot.
          </para>
          <indexterm zone="ch-system-systemd systemd-analyze">
            <primary sortas="b-systemd-analyze">systemd-analyze</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="systemd-ask-password">
        <term><command>systemd-ask-password</command></term>
        <listitem>
          <para>used to query a system password or passphrase from the user, using a
          question message specified on the command line.</para>
          <indexterm zone="ch-system-systemd systemd-ask-password">
            <primary sortas="b-systemd-ask-password">systemd-ask-password</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="systemd-cat">
        <term><command>systemd-cat</command></term>
        <listitem>
          <para>used to connect STDOUT and STDERR of a process with the Journal.
          </para>
          <indexterm zone="ch-system-systemd systemd-cat">
            <primary sortas="b-systemd-cat">systemd-cat</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="systemd-cgls">
        <term><command>systemd-cgls</command></term>
        <listitem>
          <para>recursively shows the contents of the selected Linux control group
          hierarchy in a tree.</para>
          <indexterm zone="ch-system-systemd systemd-cgls">
            <primary sortas="b-systemd-cgls">systemd-cgls</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="systemd-cgtop">
        <term><command>systemd-cgtop</command></term>
        <listitem>
          <para>shows the top control groups of the local Linux control group hierarchy,
          ordered by their CPU, memory and disk I/O load.</para>
          <indexterm zone="ch-system-systemd systemd-cgtop">
            <primary sortas="b-systemd-cgtop">systemd-cgtop</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="systemd-coredumpctl">
        <term><command>systemd-coredumpctl</command></term>
        <listitem>
          <para>used to retrieve coredumps from the Systemd Journal</para>
          <indexterm zone="ch-system-systemd systemd-coredumpctl">
            <primary sortas="b-systemd-coredumpctl">systemd-coredumpctl</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="systemd-delta">
        <term><command>systemd-delta</command></term>
        <listitem>
          <para>used to identify and compare configuration files in
          <filename class="directory">/etc</filename> that override default
          counterparts in <filename class="directory">/usr</filename>.</para>
          <indexterm zone="ch-system-systemd systemd-delta">
            <primary sortas="b-systemd-delta">systemd-delta</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="systemd-detect-virt">
        <term><command>systemd-detect-virt</command></term>
        <listitem>
          <para>detects execution in a virtualized environment.</para>
          <indexterm zone="ch-system-systemd systemd-detect-virt">
            <primary sortas="b-systemd-detect-virt">systemd-detect-virt</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="systemd-inhibit">
        <term><command>systemd-inhibit</command></term>
        <listitem>
          <para>used to execute a program with a shutdown, sleep or idle inhibitor lock
          taken.</para>
          <indexterm zone="ch-system-systemd systemd-inhibit">
            <primary sortas="b-systemd-inhibit">systemd-inhibit</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="systemd-machine-id-setup">
        <term><command>systemd-machine-id-setup</command></term>
        <listitem>
          <para>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.</para>
          <indexterm zone="ch-system-systemd systemd-machine-id-setup">
            <primary sortas="b-systemd-machine-id-setup">systemd-machine-id-setup</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="systemd-notify">
        <term><command>systemd-notify</command></term>
        <listitem>
          <para>used by daemon scripts to notify the init system about status changes.
          </para>
          <indexterm zone="ch-system-systemd systemd-notify">
            <primary sortas="b-systemd-notify">systemd-notify</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="systemd-nspawn">
        <term><command>systemd-nspawn</command></term>
        <listitem>
          <para>used to run a command or OS in a light-weight namespace container.</para>
          <indexterm zone="ch-system-systemd systemd-nspawn">
            <primary sortas="b-systemd-nspawn">systemd-nspawn</primary>
          </indexterm>
        </listitem>
      </varlistentry>

<!--      <varlistentry id="systemd-stdio-bridge">
        <term><command>systemd-stdio-bridge</command></term>
        <listitem>
          <para>To be completed</para>
          <indexterm zone="ch-system-systemd systemd-stdio-bridge">
            <primary sortas="b-systemd-stdio-bridge">systemd-stdio-bridge</primary>
          </indexterm>
        </listitem>
      </varlistentry> -->

      <varlistentry id="systemd-tmpfiles">
        <term><command>systemd-tmpfiles</command></term>
        <listitem>
          <para>creates, deletes and cleans up volatile and temporary files and directories,
          based on the configuration file format and location specified in
          <filename class="directory">tmpfiles.d</filename> directories.</para>
          <indexterm zone="ch-system-systemd systemd-tmpfiles">
            <primary sortas="b-systemd-tmpfiles">systemd-tmpfiles</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="systemd-tty-ask-password-agent">
        <term><command>systemd-tty-ask-password-agent</command></term>
        <listitem>
          <para>used to list or process pending Systemd password requests</para>
          <indexterm zone="ch-system-systemd systemd-tty-ask-password-agent">
            <primary sortas="b-systemd-tty-ask-password-agent">systemd-tty-ask-password-agent</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="telinit">
        <term><command>telinit</command></term>
        <listitem>
          <para>Tells <command>init</command> which run-level to change to.</para>
          <indexterm zone="ch-system-systemd telinit">
            <primary sortas="b-telinit">telinit</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="timedatectl">
        <term><command>timedatectl</command></term>
        <listitem>
          <para>used to query and change the system clock and its settings.
          </para>
          <indexterm zone="ch-system-systemd timedatectl">
            <primary sortas="b-timedatectl">timedatectl</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="udevadm">
        <term><command>udevadm</command></term>
        <listitem>
          <para>Generic Udev administration tool: controls the udevd daemon,
          provides info from the Udev database, monitors uevents, waits for
          uevents to finish, tests Udev configuration, and triggers uevents
          for a given device.</para>
          <indexterm zone="ch-system-systemd udevadm">
            <primary sortas="b-udevadm">udevadm</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="libsystemd-daemon">
        <term><filename class="libraryfile">libsystemd-daemon</filename></term>
        <listitem>
          <para>Systemd Daemon utility library.</para>
          <indexterm zone="ch-system-systemd libsystemd-daemon">
            <primary sortas="c-libsystemd-daemon">libsystemd-daemon</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="libsystemd-id128">
        <term><filename class="libraryfile">libsystemd-id128</filename></term>
        <listitem>
          <para>Systemd 128 Bit ID utility library.</para>
          <indexterm zone="ch-system-systemd libsystemd-id128">
            <primary sortas="c-libsystemd-id128">libsystemd-id128</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="libsystemd-journal">
        <term><filename class="libraryfile">libsystemd-journal</filename></term>
        <listitem>
          <para>Systemd Journal utility library.</para>
          <indexterm zone="ch-system-systemd libsystemd-journal">
            <primary sortas="c-libsystemd-journal">libsystemd-journal</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="libsystemd-login">
        <term><filename class="libraryfile">libsystemd-login</filename></term>
        <listitem>
          <para>Systemd Login utility library.</para>
          <indexterm zone="ch-system-systemd libsystemd-login">
            <primary sortas="c-libsystemd-login">libsystemd-login</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="libudev">
        <term><filename class="libraryfile">libudev</filename></term>
        <listitem>
          <para>A library to access Udev device information.</para>
          <indexterm zone="ch-system-systemd libudev">
            <primary sortas="c-libudev">libudev</primary>
          </indexterm>
        </listitem>
      </varlistentry>

    </variablelist>

  </sect2>

</sect1>