EMC SRDF concepts

PowerHA® SystemMirror® implements disaster recovery with SRDF storage devices by using an EMC-supplied Symmetrix command-line interface (SYMCLI).

PowerHA SystemMirror uses SYMCLI to automatically manage SRDF links and to switch the direction of the SRDF relationships when a site failover occurs. If a primary site fails, the backup site controls the PowerHA SystemMirror managed resource groups from the primary site.

PowerHA SystemMirror uses these interfaces to discover and integrate the replicated storage from an EMC storage device into the High Availability and Disaster Recovery (HADR) framework of PowerHA SystemMirror. You can use this configuration to manage the HADR framework of your applications that are using the mirrored storage devices.

Integration of SRDF and PowerHA SystemMirror provides the following benefits:
  • Support for either Prefer Primary Site or Online on Either Site inter-site management policies.
  • Flexible user-customizable resource group policies.
  • Support for cluster verification and synchronization.
  • Limited support for the PowerHA SystemMirror Cluster Single Point Of Control (C-SPOC).
  • Automatic failover and reintegration of server nodes that are attached to pairs of SRDF disk subsystems within sites and across sites.