The two-site SRDF/A configuration provide disaster restart capabilities at site DC3. Figure 3 illustrates GDDR operation in the SRDF/A environment.

Figure 3.                  GDDR Two Site SRDF/A

As Figure 3 shows, the relationship between the DC1 and DC3 sites is maintained through SRDF/A replication of primary disk images at DC1 to DC3. Both open systems (FBA) and mainframe (CKD) disk images can be replicated.

Figure 3 also shows the two GDDR C-Systems with their heartbeat communication paths, separate from the production disk and computer facilities.

GDDR does not have a requirement to “freeze” I/O to obtain a point of consistency. Multi-Session Consistency and SRDF/A provide the mechanism. At the point that GDDR receives notification of an unplanned or failure event, a point of consistency has already been achieved through these foundation technologies.

In this environment, GDDR can do the following:

• Manage planned site swaps
• Restart processing at the secondary site following unplanned primary site events
• Perform standard operational tasks:

• IPL, system reset, activate, deactivate
• Trigger stop/start of business workloads

• Actively monitor for unplanned/failure events

• Sites
• Systems
• Loss of SRDF/A
• Inter-site communication failure

• Provide Cyber Recovery from any site or from all sites