Synchronizing cluster resources
Whenever you modify the configuration of cluster resources in the Configuration Database on one node, you must synchronize the change across all cluster nodes. You perform a synchronization by choosing the Verification and Synchronization option from either the Cluster Nodes and Networks or Cluster Applications and Resources SMIT panel.
The processing performed in synchronization varies depending on whether the Cluster Manager is active on the local node:
- If the Cluster Services is not active on the local node when you select this option, the Configuration Database data in the DCD on the local node is copied to the Configuration Databases stored in the DCDs on all cluster nodes.
- If the Cluster Services is active on the local node, synchronization triggers a cluster-wide, dynamic reconfiguration event. In dynamic reconfiguration, the configuration data stored in the DCD is updated on each cluster node and, in addition, the new Configuration Database data replaces the Configuration Database data stored in the ACD on each cluster node. The cluster daemons are refreshed and the new configuration becomes the active configuration. In the PowerHA® SystemMirror® log file, reconfig_resource_release, reconfig_resource_acquire, and reconfig_resource_complete events mark the progress of the dynamic reconfiguration.
In some cases, the verification uncovers errors that do not cause the synchronization to fail. PowerHA SystemMirror reports the errors in the SMIT command status window so that you are aware of an area of the configuration that may be a problem. You should investigate any error reports, even when they do not interfere with the synchronization.
Log files that are no longer stored in a default directory, but a user-specified directory instead, are verified by the cluster verification utility, which checks that each log file has the same pathname on every node in the cluster and reports an error if this is not the case.