Saving and restoring cluster configurations

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You can use the cluster snapshot utility to save and restore cluster configurations. The cluster snapshot utility allows you to save to a file a record of all the data that defines a particular cluster configuration. This facility gives you the ability to recreate a particular cluster configuration, provided the cluster is configured with the requisite hardware and software to support the configuration.

This process is called applying a snapshot.

In addition, a snapshot can provide useful information for troubleshooting cluster problems. Because the snapshots are simple ASCII files that can be sent via e-mail, they can make remote problem determination easier.

PowerHA® SystemMirror® captures all the Cluster Aware AIX (CAA) tunables and customer security preferences in the cluster snapshot database and restores it at a later time.

Note: You can not use the cluster snapshot facility in a cluster concurrently running different versions of PowerHA SystemMirror.

By default, PowerHA SystemMirror does not collect cluster log files when you create the cluster snapshot. Cluster snapshots are used for recording the cluster configuration information, whereas cluster logs only record the operation of the cluster and not the configuration information. Skipping the log collection reduces the size of the snapshot and speeds up running the snapshot utility. The size of the cluster snapshot depends on the configuration. For instance, a basic two-node configuration requires roughly 40 KB.

Note: You can change the default to collect cluster log files using SMIT if you need logs for problem reporting. This option is available under the SMIT menu Problem Determination Tools > Log Viewing and Management > Collect Cluster log files for Problem reporting. It is recommended to use this option only if IBM® support personnel request logs.

You can also add your own custom snapshot methods to store additional user-specified cluster and system information in your snapshots. The output from these user-defined custom methods is reported along with the conventional snapshot information.