7.2.5 Configuring the Cluster Stack

To configure the cluster stack:

  1. Run the following command on each node of the cluster:

    # service o2cb configure

    The following table describes the values for which you are prompted.

    Prompt

    Description

    Load O2CB driver on boot (y/n)

    Whether the cluster stack driver should be loaded at boot time. The default response is n.

    Cluster stack backing O2CB

    The name of the cluster stack service. The default and usual response is o2cb.

    Cluster to start at boot (Enter "none" to clear)

    Enter the name of your cluster that you defined in the cluster configuration file, /etc/ocfs2/cluster.conf.

    Specify heartbeat dead threshold (>=7)

    The number of 2-second heartbeats that must elapse without response before a node is considered dead. To calculate the value to enter, divide the required threshold time period by 2 and add 1. For example, to set the threshold time period to 120 seconds, enter a value of 61. The default value is 31, which corresponds to a threshold time period of 60 seconds.

    Note

    If your system uses multipathed storage, the recommended value is 61 or greater.

    Specify network idle timeout in ms (>=5000)

    The time in milliseconds that must elapse before a network connection is considered dead. The default value is 30,000 milliseconds.

    Note

    For bonded network interfaces, the recommended value is 30,000 milliseconds or greater.

    Specify network keepalive delay in ms (>=1000)

    The maximum delay in milliseconds between sending keepalive packets to another node. The default and recommended value is 2,000 milliseconds.

    Specify network reconnect delay in ms (>=2000)

    The minimum delay in milliseconds between reconnection attempts if a network connection goes down. The default and recommended value is 2,000 milliseconds.

    To verify the settings for the cluster stack, enter the service o2cb status command:

    # service o2cb status
    Driver for "configfs": Loaded
    Filesystem "configfs": Mounted
    Stack glue driver: Loaded
    Stack plugin "o2cb": Loaded
    Driver for "ocfs2_dlmfs": Loaded
    Filesystem "ocfs2_dlmfs": Mounted
    Checking O2CB cluster "mycluster": Online
      Heartbeat dead threshold: 61
      Network idle timeout: 30000
      Network keepalive delay: 2000
      Network reconnect delay: 2000
      Heartbeat mode: Local
    Checking O2CB heartbeat: Active

    In this example, the cluster is online and is using local heartbeat mode. If no volumes have been configured, the O2CB heartbeat is shown as Not active rather than Active.

    The next example shows the command output for an online cluster that is using three global heartbeat devices:

    # service o2cb status
    Driver for "configfs": Loaded
    Filesystem "configfs": Mounted
    Stack glue driver: Loaded
    Stack plugin "o2cb": Loaded
    Driver for "ocfs2_dlmfs": Loaded
    Filesystem "ocfs2_dlmfs": Mounted
    Checking O2CB cluster "mycluster": Online
      Heartbeat dead threshold: 61
      Network idle timeout: 30000
      Network keepalive delay: 2000
      Network reconnect delay: 2000
      Heartbeat mode: Global
    Checking O2CB heartbeat: Active
      7DA5015346C245E6A41AA85E2E7EA3CF /dev/sdd
      4F9FBB0D9B6341729F21A8891B9A05BD /dev/sdg
      B423C7EEE9FC426790FC411972C91CC3 /dev/sdj
  2. Configure the o2cb and ocfs2 services so that they start at boot time after networking is enabled:

    # chkconfig o2cb on
    # chkconfig ocfs2 on

    These settings allow the node to mount OCFS2 volumes automatically when the system starts.