PDSE extended generation grouping for tiered storage systems

A computer program product for storing data, the computer program product comprising a computer-readable storage medium having computer-usable program code embodied therein, the computer-usable program code comprising:

• computer-usable program code to establish an extended generation group comprising a plurality of data sets, the plurality of data sets comprising a first data set containing primary members and a first number of generations of each of the primary members, and a second data set containing a second number of generations of each of the primary members, wherein the first data set and the second data set are stored on different tiers of a tiered storage system;
• computer-usable program code to indicate, in metadata of the first data set, a first maximum number of generations allowable in the first data set;
• computer-usable program code to derive, from the first maximum number, a second maximum number of generations allowable in the second data set, such that the second maximum number is directly related to the first maximum number;
• and
• computer-usable program code to, upon modifying a primary member in the first data set, automatically move an oldest generation in the first data set to the second data set, and delete an oldest generation in the second data set to ensure that the first number does not exceed the first maximum number, and the second number does not exceed the second maximum number.

A system for storing data, the system comprising:

• at least one processor;
• at least one memory device operably coupled to the at least one processor and storing instructions for execution on the at least one processor, the instructions causing the at least one processor to:
• establish an extended generation group comprising a plurality of data sets, the plurality of data sets comprising a first data set containing primary members and a first number of generations of each of the primary members, and a second data set containing a second number of generations of each of the primary members, wherein the first data set and the second data set are stored on different tiers of a tiered storage system;
• indicate, in metadata of the first data set, a first maximum number of generations allowable in the first data set;
• derive, from the first maximum number, a second maximum number of generations allowable in the second data set, such that the second maximum number is directly related to the first maximum number;
• and
• upon modifying a primary member in the first data set, automatically move an oldest generation in the first data set to the second data set, and delete an oldest generation in the second data set to ensure that the first number does not exceed the first maximum number, and the second number does not exceed the second maximum number.