Configuring NTP clients

Use this procedure to configure a delegate hosts to synchronize its clocks with the NTP server on the Control Center master host. Perform this procedure only if the hosts do not have internet access. Repeat this procedure on each Control Center delegate host.

  1. Log in to the Control Center delegate host as root, or as a user with superuser privileges.
  2. Create a backup of the NTP configuration file.
    cp -p /etc/ntp.conf /etc/ntp.conf.orig
  3. Edit the NTP configuration file./
    1. Open /etc/ntp.conf with a text editor.
    2. Replace all of the lines in the file with the following lines:
      # Point to the master time server
      server MASTER_ADDRESS
      restrict default ignore
      restrict MASTER_ADDRESS mask nomodify notrap noquery
      driftfile /var/lib/ntp/drift
    3. Replace both instances of MASTER_ADDRESS with the virtual IP address (HA-Virtual-IP) of the high-availability cluster.
    4. Save the file and exit the editor.
  4. Synchronize the clock with the master server.
    ntpd -gq
  5. Enable and start the NTP daemon.
    1. Enable the ntpd daemon.
      systemctl enable ntpd
    2. Configure ntpd to start when the system starts.
      Currently, an unresolved issue associated with NTP prevents ntpd from restarting correctly after a reboot, and the following commands provide a workaround to ensure that it does.
      echo "systemctl start ntpd" >> /etc/rc.d/rc.local
      chmod +x /etc/rc.d/rc.local
    3. Start ntpd.
      systemctl start ntpd