Sun Cluster Software Installation Guide for Solaris OS

How to Configure Network Time Protocol (NTP)

Perform this task to create or modify the NTP configuration file after you install Sun Cluster software. You must also modify the NTP configuration file when you add a node to an existing cluster or when you change the private hostname of a node in the cluster. If you added a node to a single-node cluster, you must ensure that the NTP configuration file that you use is copied to the original cluster node.

The primary requirement when you configure NTP, or any time synchronization facility within the cluster, is that all cluster nodes must be synchronized to the same time. Consider accuracy of time on individual nodes to be of secondary importance to the synchronization of time among nodes. You are free to configure NTP as best meets your individual needs if this basic requirement for synchronization is met.

See the Sun Cluster Concepts Guide for Solaris OS for further information about cluster time. See the /etc/inet/ntp.cluster template file for additional guidelines on how to configure NTP for a Sun Cluster configuration.

  1. If you installed your own /etc/inet/ntp.conf file before you installed Sun Cluster software, you do not need to modify your ntp.conf file.

    Skip to Step 8.

  2. Become superuser on a cluster node.

  3. If you have your own file, copy your file to each node of the cluster.

  4. If you do not have your own /etc/inet/ntp.conf file to install, use the /etc/inet/ntp.conf.cluster file as your NTP configuration file.

    Note –

    Do not rename the ntp.conf.cluster file as ntp.conf.

    If the /etc/inet/ntp.conf.cluster file does not exist on the node, you might have an /etc/inet/ntp.conf file from an earlier installation of Sun Cluster software. Sun Cluster software creates the /etc/inet/ntp.conf.cluster file as the NTP configuration file if an /etc/inet/ntp.conf file is not already present on the node. If so, perform the following edits instead on that ntp.conf file.

    1. Use your preferred text editor to open the /etc/inet/ntp.conf.cluster file on one node of the cluster for editing.

    2. Ensure that an entry exists for the private hostname of each cluster node.

      If you changed any node's private hostname, ensure that the NTP configuration file contains the new private hostname.

    3. Remove any unused private hostnames.

      The ntp.conf.cluster file might contain nonexistent private hostnames. When a node is rebooted, the system generates error messages as the node attempts to contact those nonexistent private hostnames.

    4. If necessary, make other modifications to meet your NTP requirements.

  5. Copy the NTP configuration file to all nodes in the cluster.

    The contents of the NTP configuration file must be identical on all cluster nodes.

  6. Stop the NTP daemon on each node.

    Wait for the stop command to complete successfully on each node before you proceed to Step 7.

    # /etc/init.d/xntpd stop

  7. Restart the NTP daemon on each node.

    • If you use the ntp.conf.cluster file, run the following command:

      # /etc/init.d/xntpd.cluster start

      The xntpd.cluster startup script first looks for the /etc/inet/ntp.conf file. If that file exists, the script exits immediately without starting the NTP daemon. If the ntp.conf file does not exist but the ntp.conf.cluster file does exist, the script starts the NTP daemon. In this case, the script uses the ntp.conf.cluster file as the NTP configuration file.

    • If you use the ntp.conf file, run the following command:

      # /etc/init.d/xntpd start
  8. (Optional) SPARC: Configure Sun Management Center to monitor the cluster.

    Go to SPARC: Installing the Sun Cluster Module for Sun Management Center.

  9. Install third-party applications, register resource types, set up resource groups, and configure data services.

    See the documentation that is supplied with the application software and the Sun Cluster Data Services Planning and Administration Guide for Solaris OS.