At this point, you have completed configuring SADTA in the 3DC solution with the RAC database. It is recommended that you verify the setup during the planned downtime for maintenance using the procedure mentioned in “Verifying the Three Data Center Environment” (page 461).

Verifying the Three Data Center Environment

To verify the setup:

Preview the data replication storage failover by using the cmdrprev command.

Test the application startup at the recovery cluster.

Test Continentalclusters recovery using the cmrecovercl command in the recovery cluster.

Previewing the Data Replication Storage Failover by Using cmdrprev

To preview the data replication storage failover and to identify potential problems that can cause Metrocluster package failover or Continentalclusters recovery to fail, run the following command on all nodes in the 3DC solution:

# cmdrprev {[–p <package_name>] [-e <Metrocluster_environment_file>]

The cmdrprev command previews the failover of the data replication storage that indicates if the storage preparation will be successful or not in event of an actual package failover.

The storage failover can fail due to many reasons and can be categorized as the following:

Incorrect configuration or setup of 3DC environment

Invalid RAID Manager configuration file

The command device is not functional

The installed Metrocluster binaries are corrupt

Incorrect file permissions

Invalid data replication state

The data may not be in the write-order, which can be due to a track copy at the time of the failover attempt.

The data is not current (lagging behind the primary) and the 3DC parameters configured in the package are not set correctly to allow a failover on non-current data.

The command parses the Metrocluster Environment file associated to the <package name> or which is provided as the input parameter <Metrocluster env file>with the -eoption. It ensures proper syntax, and verifies for valid parameter values. The cmdrprev command previews the data replication preparation steps based on the values in the Metrocluster environment file and the current state of replication. This command displays a detailed log of all the preparation steps and the changes to the data replication environment that would have been done in case of an actual preparation. The command does not change the data replication environment and can be used even if the package associated with the data replication storage is up on the cluster.

NOTE: Detailed messages from the preview process are logged into stdout.

The command exit value indicates if the storage failover in an actual package will succeed or not. Table 32 (page 462) describes the exit values of the command.

Verifying the Three Data Center Environment 461