Standby DB for SAP portal (portal DR)

We have a sap portal running 7.02. My requirement is to have a poral DR setup.

Current Scenario

Running portal in Cluster setup with Oracle Rac (3 node)

Another 3 node cluster available for disaster recovery landscape but the hostanames are diffrent. So my PROD portal hostname is sapEPCI but DR hostanme is sapepcidr. That is stopping me from connecting SAP to DB as hostanames are stored in DB as well as file system in portal.

How to achieve a DR setup in standby mode (oracle db) for sap portal when I am changing hostnames?

Do I need to use a application sync software to depoly new changes in DR setup?

BTW : all my Abap instances are working with this DR setup as ABAP has nothing in file system.

Your early reply is really appreciated.