source: networking/netprogs/rsync.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
  <!ENTITY % general-entities SYSTEM "../../general.ent">
  %general-entities;

  <!ENTITY rsync-download-http "https://www.samba.org/ftp/rsync/src/rsync-&rsync-version;.tar.gz">
  <!ENTITY rsync-download-ftp  " ">
  <!ENTITY rsync-md5sum        "f5c17f9c9164ef9e60d9d8c96b23da06">
  <!ENTITY rsync-size          "1.2 MB">
  <!ENTITY rsync-buildsize     "9.2 MB (with tests; add 24 MB for HTML API documentation)">
  <!ENTITY rsync-time          "0.7 SBU (with tests)">
]>

<sect1 id="rsync" xreflabel="rsync-&rsync-version;">
  <?dbhtml filename="rsync.html"?>


  <title>rsync-&rsync-version;</title>

  <indexterm zone="rsync">
    <primary sortas="a-rsync">rsync</primary>
  </indexterm>

  <sect2 role="package">
    <title>Introduction to rsync</title>

    <para>
      The <application>rsync</application> package contains the
      <command>rsync</command> utility. This is useful for synchronizing large
      file archives over a network.
    </para>

    &lfs121_checked;

    <bridgehead renderas="sect3">Package Information</bridgehead>
    <itemizedlist spacing="compact">
      <listitem>
        <para>
          Download (HTTP): <ulink url="&rsync-download-http;"/>
        </para>
      </listitem>
      <listitem>
        <para>
          Download (FTP): <ulink url="&rsync-download-ftp;"/>
        </para>
      </listitem>
      <listitem>
        <para>
          Download MD5 sum: &rsync-md5sum;
        </para>
      </listitem>
      <listitem>
        <para>
          Download size: &rsync-size;
        </para>
      </listitem>
      <listitem>
        <para>
          Estimated disk space required: &rsync-buildsize;
        </para>
      </listitem>
      <listitem>
        <para>
          Estimated build time: &rsync-time;
        </para>
      </listitem>
    </itemizedlist>

    <bridgehead renderas="sect3">rsync Dependencies</bridgehead>

    <!-- This now uses LZ4, OpenSSL, and zstd from LFS. -->
    <bridgehead renderas="sect4">Recommended</bridgehead>
    <para role="recommended">
      <xref linkend="popt"/>
    </para>

    <bridgehead renderas="sect4">Optional</bridgehead>
    <para role="optional">
      <xref linkend="doxygen"/> and
      <ulink url="https://cyan4973.github.io/xxHash/">xxhash</ulink>
    </para>

  </sect2>

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

    <para>
      For security reasons, running the <application>rsync</application>
      server as an unprivileged user and group is encouraged. If you intend to
      run <command>rsync</command> as a daemon, create the
      <systemitem class="username">rsyncd</systemitem> user and group
      with the following commands issued by the
      <systemitem class="username">root</systemitem> user:
    </para>

<screen role="root"><userinput>groupadd -g 48 rsyncd &amp;&amp;
useradd -c "rsyncd Daemon" -m -d /home/rsync -g rsyncd \
    -s /bin/false -u 48 rsyncd</userinput></screen>

    <para>
      Install <application>rsync</application> by running the following
      commands:
    </para>

<screen><userinput>./configure --prefix=/usr    \
            --disable-xxhash \
            --without-included-zlib &amp;&amp;
make</userinput></screen>

    <para>
      If you have <xref linkend="doxygen"/> installed and wish to
      build HTML API documentation, issue:
    </para>

<screen remap="doc"><userinput>doxygen</userinput></screen>

    <para>
      To test the results, issue: <command>make check</command>.
    </para>

    <para>
      Now, as the <systemitem class="username">root</systemitem> user:
    </para>

<screen role='root'><userinput>make install</userinput></screen>

    <para>
      If you built the documentation, install it using the following
      commands as the <systemitem class="username">root</systemitem> user:
    </para>

<screen role='root'
        remap="doc"><userinput>install -v -m755 -d          /usr/share/doc/rsync-&rsync-version;/api &amp;&amp;
install -v -m644 dox/html/*  /usr/share/doc/rsync-&rsync-version;/api</userinput></screen>

  </sect2>

  <sect2 role="commands">
    <title>Command Explanations</title>

    <para>
      <parameter>--disable-xxhash</parameter>: This switch disables advanced
      xxhash checksum support. Remove this switch if you have installed
      <ulink url="https://cyan4973.github.io/xxHash/">xxhash</ulink>.
    </para>

    <para>
      <parameter>--without-included-zlib</parameter>: This switch enables
      compilation with the system-installed zlib library.
    </para>

  </sect2>

  <sect2 role="configuration">
    <title>Configuring rsync</title>

    <sect3 id="rsync-config">
      <title>Config Files</title>

      <para>
        <filename>/etc/rsyncd.conf</filename>
      </para>

      <indexterm zone="rsync rsync-config">
        <primary sortas="e-etc-rsyncd.conf">/etc/rsyncd.conf</primary>
      </indexterm>

    </sect3>

    <sect3>
      <title>Configuration Information</title>

      <para>
        For client access to remote files, you may need to install the
        <xref linkend="openssh"/> package to connect to the remote server.
      </para>

      <para>
        This is a simple download-only configuration to set up running
        <command>rsync</command> as a server. See the <ulink role='man'
        url='&man;rsyncd.conf.5'>rsyncd.conf(5)</ulink>
        man-page for additional options (i.e., user authentication).
      </para>

<screen role="root"><userinput>cat &gt; /etc/rsyncd.conf &lt;&lt; "EOF"
<literal># This is a basic rsync configuration file
# It exports a single module without user authentication.

motd file = /home/rsync/welcome.msg
use chroot = yes

[localhost]
    path = /home/rsync
    comment = Default rsync module
    read only = yes
    list = yes
    uid = rsyncd
    gid = rsyncd
</literal>
EOF</userinput></screen>

      <para>
        You can find additional configuration information and general
        documentation about <command>rsync</command> at
        <ulink url="https://rsync.samba.org/documentation.html"/>.
      </para>

    </sect3>

    <sect3 id="rsync-init">
      <title><phrase revision="sysv">Boot Script</phrase>
             <phrase revision="systemd">Systemd Unit</phrase></title>

      <para>
        Note that you only need to start the
        <application>rsync</application> server if you want to provide an
        <application>rsync</application> archive on your local machine.
        You don't need this <phrase revision="sysv">script</phrase>
        <phrase revision="systemd">unit</phrase> to run the
        <application>rsync</application> client.
      </para>

      <para>
        Install the
        <phrase revision="sysv"><filename>/etc/rc.d/init.d/rsyncd</filename>
        init script</phrase>
        <phrase revision="systemd"><filename>rsyncd.service</filename>
        unit</phrase> included in the
        <xref linkend="bootscripts" revision="sysv"/>
        <xref linkend="systemd-units" revision="systemd"/> package.
      </para>

<screen role="root"><userinput>make install-rsyncd</userinput></screen>

      <note revision="systemd">
        <para>
          This package comes with two types of units: A service file and a
          socket file. The service file will start rsync daemon once at boot
          and it will keep running until the system shuts down. The socket file
          will make systemd listen on rsync port (Default 873, needs to be
          edited for anything else) and will start rsync daemon when something
          tries to connect to that port and stop the daemon when the connection
          is terminated. This is called socket activation and is analogous to
          using <application>{,x}inetd</application> on a SysVinit based
          system.
        </para>

        <para>
          By default, the first method is used - rsync daemon is started
          at boot and stopped at shutdown. If the socket method is desired, you
          need to run as the
          <systemitem class="username">root</systemitem> user:
        </para>

<screen role="nodump"><userinput>systemctl stop rsyncd &amp;&amp;
systemctl disable rsyncd &amp;&amp;
systemctl enable rsyncd.socket &amp;&amp;
systemctl start rsyncd.socket</userinput></screen>

        <para>
          Note that socket method is only useful for remote backups. For
          local backups you'll need the service method.
        </para>
      </note>

    </sect3>

  </sect2>

  <sect2 role="content">
    <title>Contents</title>

    <segmentedlist>
      <segtitle>Installed Program</segtitle>
      <segtitle>Installed Libraries</segtitle>
      <segtitle>Installed Directories</segtitle>

      <seglistitem>
        <seg>rsync and rsync-ssl</seg>
        <seg>None</seg>
        <seg>Optionally, /usr/share/doc/rsync-&rsync-version;</seg>
      </seglistitem>
    </segmentedlist>

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

      <varlistentry id="rsync-prog">
        <term><command>rsync</command></term>
        <listitem>
          <para>
            is a replacement for <command>rcp</command> (and
            <command>scp</command>) that has many more features. It uses the
            <quote>rsync algorithm</quote> which provides a very fast method of
            syncing remote files. It does this by sending just the differences
            in the files across the link, without requiring that both sets of
            files are present at one end of the link beforehand
          </para>
          <indexterm zone="rsync rsync-prog">
            <primary sortas="b-rsync">rsync</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="rsync-ssl">
        <term><command>rsync-ssl</command></term>
        <listitem>
          <para>
            is a helper script used when connecting to an rsync daemon that
            has SSL support built in
          </para>
          <indexterm zone="rsync rsync-ssl">
            <primary sortas="b-rsync-ssl">rsync-ssl</primary>
          </indexterm>
        </listitem>
      </varlistentry>

    </variablelist>

  </sect2>

</sect1>