Requirements and Restrictions When Using Storage-Based Data Replication Within a Cluster

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.

• Node-to-node distance is limited by the Sun Cluster Fibre Channel and interconnect infrastructure. Contact your Sun 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 and Hitachi TrueCopy allow the user to define groups of replicated devices. The replication device group and Sun Cluster global device group must be given the same name so that they may be moved between nodes as a single unit.

• 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.

• 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.

• Oracle Real Application Clusters (RAC) is not supported with SRDF and Hitachi TrueCopy 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.

• Veritas Cluster Volume Manager (CVM) and Solaris Volume Manager (SVM) OBAN cluster for Sun Cluster software are not supported.