Application Environment Clones
A duplicate of an entire DB2 subsystem is called a DB2 clone, analogous there are IMS clones or combined IMS/DB2 clones. Cloning normally means to duplicate all the volumes on which the systems reside. The volume duplicates are then processed to provide separate systems or “clones” that contain the same data as the originals. Clones are mainly required for test, in particular for licensed software. Clones are eminently suited as data base for test data management or for system upgrade testing. Provisioning is fast which means that consistent data is captured without noticeable impact on production. Access to the clone is possible at anytime and production is isolated, only the regular clone refresh procedure requires access rights for production. Clones are well-suited as pre-production environments for acceptance testing, performance analysis and regression testing.

z/OS volumes can be copied fast and efficiently. However, to provide a clone it is still required to rename and re-catalog all the datasets on the duplicated volumes in order to make them generally accessible. Afterwards the clone is still not ready, DB2, particularly the DB2 catalog, and IMS, if involved, must still be adapted to the new dataset names. Cloning tools automate the whole cloning process, they identify the volumes to be copied, generate the jobs to copy the volumes, rename and re-catalog the datasets, and adapt DB2 and IMS. Once the cloning tool finished its work the clone, i.e. the test environment, is ready for use.