System and method for demand-based data recovery

A system and method for demand-based data recovery operating in a computerized data processing system that includes a computer platform operable under the control of system data, including system programs, catalogs, directories, inventories and the like, and one or more user applications operable in conjunction with user data. The data processing system includes a data backup and recovery system for periodically transferring data between one or more primary data storage resources and one or more secondary data storage resources. The demand-based system and method operate to recover data from the secondary data storage resources to the primary data storage resources following a disaster event resulting in the loss of all or a portion of the data on the primary data storage resources. In accordance therewith, the system data is first recovered from the secondary data storage resources to the primary data storage resources. Execution of the one or more user applications is next commenced but the user data is not immediately recovered. Only if the application requests non-recovered user data will the requested data be recovered from the secondary data storage resources to the primary data storage resources. The demand-based system and method can be adapted to recover entire data sets (e.g. files) from a previous full backup or it can recover data subsets (e.g. records) in either a full backup mode or a change-data-only mode.