2.1.2.2 Cluster Reconfiguration

Any time there is a change in the state of the cluster (in the form of a node leaving or joining), a cluster reconfiguration occurs. The cluster manager for each node monitors other nodes in the cluster and calls the cluster reconfiguration utility, vxclust, when there is a change in cluster membership. vxclust coordinates cluster reconfigurations and provides communication between CVM and the cluster manager. The cluster manager and vxclust work together to ensure that each step in the cluster reconfiguration is completed in the correct order.

During a cluster reconfiguration, I/O to shared disks is suspended. It is resumed when the reconfiguration completes. Applications can therefore appear to be frozen for a short time.

If other operations (such as volume manager operations or recoveries) are in progress, the cluster reconfiguration can be delayed until those operations have completed. Volume reconfigurations (described later) do not take place at the same time as cluster reconfigurations. Depending on the circumstances, an operation can be held up and restarted later. In most cases, cluster reconfiguration takes precedence. However, if the volume reconfiguration is in the commit stage, it will complete first.

For further information on cluster reconfiguration, refer to "2.2.1 The vxclust Command".