SAP HANA Multitarget System Replication Setup

Hi , I am Setting up HANA Multitarget System Replication Setup. 2 Nodes at Primary site running on Suse / SAP Cluster and further 2 nodes running at DR site ( different Cluster ) .primary system A in data center 1 replicates data changes to secondary system B in the same data center. Primary system A also replicates data changes to secondary system C in data center 2. Secondary system C is a source system for a further secondary system D located in the same data center with system C.

Could any one suggest what are the best practice to keep DR system . they will be on maintenance mode during normal business days and needs to be active once DR trigger.