To ensure data integrity, use multipathing and the proper RAID package. The following list includes considerations for implementing a cluster configuration that uses storage-based data replication.
If configuring the cluster for automatic failover, use synchronous replication.
For instructions on configuring the cluster for automatic failover of replicated volumes, see Administering Storage-Based Replicated Devices. For details on the requirements to design a campus cluster, see Shared Data Storage in Oracle Solaris Cluster 4.2 Hardware Administration Manual .
Particular application-specific data might not be suitable for asynchronous data replication. Use your understanding of your application's behavior to determine how best to replicate application-specific data across the storage devices.
Node-to-node distance is limited by the Oracle Solaris Cluster Fibre Channel and interconnect infrastructure. Contact your Oracle service provider for more information about current limitations and supported technologies.
Do not configure a replicated volume as a quorum device. Locate any quorum devices on a shared, unreplicated volume or use the quorum server.
Ensure that only the primary copy of the data is visible to cluster nodes. Otherwise, the volume manager might try to simultaneously access both primary and secondary copies of the data. Refer to the documentation that was shipped with your storage array for information about controlling the visibility of your data copies.
EMC SRDF allows the user to define groups of replicated devices. Each replication device group requires an Oracle Solaris Cluster device group with the same name.
For a three-site or three-data-center configuration using EMC SRDF with concurrent or cascaded RDF devices, you must add the following entry in the Solutions Enabler SYMCLI options file on all participating cluster nodes:
SYMAPI_2SITE_CLUSTER_DG=device-group:rdf-group-number
This entry enables the cluster software to automate the movement of the application between the two SRDF synchronous sites. The rdf-group-number in the entry represents the RDF group that connects the host's local symmetrix to the second site's symmetrix.
For more information about three-data-center configurations, see Three-Data-Center (3DC) Topologies in Oracle Solaris Cluster Geographic Edition Overview .
Oracle Real Application Clusters (Oracle RAC) is not supported with SRDF when replicating within a cluster. Nodes connected to replicas that are not currently the primary replica will not have write access. Any scalable application that requires direct write access from all nodes of the cluster cannot be supported with replicated devices.
The multi-owner Solaris Volume Manager for Oracle Solaris Cluster software are not supported.
Do not use the Domino mode or Adaptive Copy mode in EMC SRDF. See Using Storage-Based Data Replication Within a Cluster for more information.