Red Hat ENTERPRISE LINUX 5 - ADMINISTRATION Manual

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Configuring Cluster Properties53Parameter DescriptionLabel Specifies the quorum disk label created by the mkqdisk utility. If this fieldcontains an entry, the label overrides the Device field. If this field is used,the quorum daemon reads /proc/partitions and checks for qdisksignatures on every block device found, comparing the label against thespecified label. This is useful in configurations where the quorum devicename differs among nodes.Quorum DiskHeuristicsProgram — The program used to determine if this heuristic is alive. Thiscan be anything that can be executed by /bin/sh -c. A return value of 0indicates success; anything else indicates failure. This field is required.Score — The weight of this heuristic. Be careful when determining scoresfor heuristics. The default score for each heuristic is 1.Interval — The frequency (in seconds) at which the heuristic is polled. Thedefault interval for every heuristic is 2 seconds.Table 5.1. Quorum-Disk Parameters5.3. Configuring Cluster PropertiesIn addition to configuring cluster parameters in the preceding section (Section 5.2, “Starting theCluster Configuration Tool”), you can configure the following cluster properties: Cluster Alias(optional), a Config Version (optional), and Fence Daemon Properties. To configure clusterproperties, follow these steps:1. At the left frame, click Cluster.2. At the bottom of the right frame (labeled Properties), click the Edit Cluster Properties button.Clicking that button causes a Cluster Properties dialog box to be displayed. The ClusterProperties dialog box presents text boxes for Cluster Alias, Config Version, and two FenceDaemon Properties parameters: Post-Join Delay and Post-Fail Delay.3. (Optional) At the Cluster Alias text box, specify a cluster alias for the cluster. The default clusteralias is set to the true cluster name provided when the cluster is set up (refer to Section 5.2,“Starting the Cluster Configuration Tool”). The cluster alias should be descriptive enough todistinguish it from other clusters and systems on your network (for example, nfs_cluster orhttpd_cluster). The cluster alias cannot exceed 15 characters.4. (Optional) The Config Version value is set to 1 by default and is automatically incremented eachtime you save your cluster configuration. However, if you need to set it to another value, you canspecify it at the Config Version text box.5. Specify the Fence Daemon Properties parameters: Post-Join Delay and Post-Fail Delay.a. The Post-Join Delay parameter is the number of seconds the fence daemon (fenced) waitsbefore fencing a node after the node joins the fence domain. The Post-Join Delay defaultvalue is 3. A typical setting for Post-Join Delay is between 20 and 30 seconds, but can varyaccording to cluster and network performance.b. The Post-Fail Delay parameter is the number of seconds the fence daemon (fenced) waitsbefore fencing a node (a member of the fence domain) after the node has failed.The Post-FailDelay default value is 0. Its value may be varied to suit cluster and network performance.