Preventing inefficient recalls in a hierarchical storage management (hsm) system

A system for preventing inefficient recalls in a hierarchical storage management (HSM) system, comprising:

• one or more computers with executable instructions that when executed cause the system to:
• receive difference data for updating a target file stored in a first storage system having at least an upper storage layer and a lower tape layer;
• store the difference data in a stub file located on the upper storage layer and corresponding to the target file in the first storage system located on the lower tape layer;
• execute a recall operation that copies the target file from the lower tape layer to the upper storage layer;
• and
• copy the difference data stored in the stub file to the target file copied onto the upper storage layer from the lower tape layer according to one or more predetermined events.

A computer program product for, by a processor, preventing inefficient recalls in a hierarchical storage management (HSM) system, the computer program product comprising a non-transitory computer-readable storage medium having computer-readable program code portions stored therein, the computer-readable program code portions comprising:

• an executable portion that receives difference data for updating a target file stored in a first storage system having at least an upper storage layer and a lower tape layer;
• an executable portion that stores the difference data in a stub file located on the upper storage layer and corresponding to the target file in the first storage system located on the lower tape layer;
• an executable portion that executes a recall operation that copies the target file from the lower tape layer to the upper storage layer;
• and
• an executable portion that copies the difference data stored in the stub file to the target file copied onto the upper storage layer from the lower tape layer according to one or more predetermined events