installing-ntp.xml

<?xml version="1.0" encoding="UTF-8"?>
<section xml:id="installing-ntp"
    xmlns="http://docbook.org/ns/docbook"
    xmlns:xi="http://www.w3.org/2001/XInclude"
    xmlns:xlink="http://www.w3.org/1999/xlink" version="5.0">
    <title>Installing Network Time Protocol (NTP)</title>
    <para>To keep all the services in sync across multiple machines,
        you need to install NTP, and if you do a multi-node
        configuration you will configure one server to be the
        reference server.</para>
    <screen os="ubuntu"><userinput><prompt>$</prompt> sudo apt-get install -y ntp</userinput></screen>
    <screen os="rhel;fedora;centos"><prompt>$</prompt> <userinput>sudo yum install -y ntp</userinput></screen>
    <para>Set up the NTP server on your controller node so that it
        receives data by modifying the <filename>ntp.conf</filename>
        file and restarting the service. As root:</para>
    <screen os="ubuntu"><prompt>#</prompt> <userinput>sed -i 's/server ntp.ubuntu.com/server ntp.ubuntu.com\nserver 127.127.1.0\nfudge 127.127.1.0 stratum 10/g' /etc/ntp.conf</userinput>
<prompt>#</prompt> <userinput>service ntp restart</userinput></screen>
   <screen os="rhel;fedora;centos"><prompt>$</prompt> <userinput>sudo service ntpd start</userinput>
<prompt>$</prompt> <userinput>sudo chkconfig ntpd on</userinput></screen>
    <para>Set up the NTP client on your compute node so that the time
        between controller node and compute node is synchronized.
        Install the NTP package on the compute nodes in addition to
        the API nodes, to allow more gradual time updates. </para>
</section>