Best Practices When Using Storage-Based Data Replication

When setting up device groups that use the Hitachi TrueCopy or Hitachi Universal Replicator software for storage-based data replication, observe the following practices:

• Use synchronous replication to avoid the possibility of lost data if the primary site fails.

• A one-to-one relationship should exist between the Sun Cluster global device group and the TrueCopy replication group defined in the horcm configuration file. This allows both groups to move from node to node as a single unit.

• Global file system volumes and failover file system volumes cannot be mixed in the same replicated device group because they are controlled differently. Global file systems are controlled by a Device Configuration System (DCS), while failover file system volumes are controlled by HAS+. The primary for each could be a different node, causing conflicts on which node should be the replication primary.

• All RAID manager instances should be up and running at all times.

When using EMC SRDF software for storage-based data replication, use dynamic devices instead of static devices. Static devices require several minutes to change the replication primary and can impact failover time.