/sys$common/syshlp/HELPLIB.HLB  —  SET  CLUSTER

1    /EXPECTED_VOTES 

    Sets the total expected votes in the OpenVMS Cluster to a value
    that you specify or, if no value is specified, sets the total
    votes to a value determined by the system.

    Requires OPER (operator) privilege.

    Format

      SET CLUSTER/EXPECTED_VOTES[=value]

1.1  –  Parameter 

 value

    Specifies the total number of expected votes in the cluster.

1.2  –  Description 

    The SET CLUSTER/EXPECTED_VOTES command enables you to adjust the
    total number of expected votes in the cluster. Set this value
    equal to the number of votes contributed by each node plus the
    number of votes contributed by the cluster quorum disk. The
    system will automatically calculate the value of the cluster
    quorum from the total number of expected votes in the cluster.

    You can specify the expected total votes value as part of the
    SET CLUSTER/EXPECTED_VOTES command string. If you enter the
    command without specifying a value for expected votes, the system
    calculates the value for you, using the following formula:

    EXPECTED_VOTES=(NODE1_VOTES+NODE2_VOTES+...)+QUORUM_DISK_VOTES

    NODEn_VOTES is the value of the system parameter VOTES for each
    node in the cluster and QUORUM_DISK_VOTES is the value of the
    system parameter QDSKVOTES.

    When you enter the SET CLUSTER/EXPECTED_VOTES command without
    specifying a value, the system assumes that all nodes that are
    expected to be in the cluster are currently members.

    In general, you use the SET CLUSTER/EXPECTED_VOTES command only
    when a node is leaving the cluster for an extended period of
    time. Under normal circumstances, quorum is not reduced when a
    node leaves the cluster, because it is assumed that the node may
    be rebooted and rejoin the cluster. If a node is removed and is
    unable to rejoin the cluster within a reasonable period of time
    (for example, if a node crashes due to a hardware problem and
    cannot rejoin the cluster for several days), the quorum for the
    cluster can safely be reduced by lowering the total expected
    votes until that node rejoins.

    The purpose of a cluster quorum is to eliminate any possibility
    of the cluster partitioning into separate clusters and
    simultaneously accessing the same resources (such as disks).
    If the sum of the votes for all members of the cluster is smaller
    than the cluster quorum, all nodes will block activity until new
    nodes join to increase the vote total. Lowering the quorum value
    (by reducing the value of the total expected votes) when one or
    more nodes leave the cluster for long periods of time reduces
    this possibility.

    Note that no matter what value you specify for the SET
    CLUSTER/EXPECTED_VOTES command, you cannot increase quorum to
    a value that is greater than the number of the votes present,
    nor can you reduce quorum to a value that is half or fewer of the
    votes present.

    When you enter the SET CLUSTER/EXPECTED_VOTES command, either
    with or without an expected votes value specified, the system
    responds with a message indicating the new value that was
    actually set. Note that you need to enter this command only on
    one node in the cluster, because the new value for total expected
    votes is propagated through the cluster. This new expected votes
    value should then be stored in the system parameter EXPECTED_
    VOTES on each node, so that it remains in effect after the nodes
    reboot.

    When a node that was previously a member of the cluster is
    ready to rejoin, you should increase the system parameter
    EXPECTED_VOTES to its original value before bringing the node
    back to the cluster. Note that you do not need to use the SET
    CLUSTER/EXPECTED_VOTES command to increase the number of expected
    votes, because the expected votes value will be increased
    automatically when the node rejoins the cluster.

1.3  –  Examples 

    1.$ SET CLUSTER/EXPECTED_VOTES

      The SET CLUSTER command in this example instructs the system
      to calculate the total expected votes value for you, because
      no value is specified as part of the command string. The system
      uses the NODEn_VOTES + QUORUM_DISK_VOTES formula.

    2.$ SET CLUSTER/EXPECTED_VOTES=9

      The SET CLUSTER command in this example sets the total expected
      votes to 9, which is the value specified in the command string.
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