Reducing the amount of data transferred to remote storage locations for modified objects

A computer-implemented method, comprising:

• receiving, by the computer, a recall request from a remote location for data which corresponds to a data access request;
• sending, by the computer, a copy of an existing object which includes more than one block to the remote location, wherein the data which corresponds to the data access request is stored in at least one of the blocks;
• receiving, by the computer, a sparse object from the remote location, wherein the sparse object only includes ones of the blocks which contain data that has been modified;
• and
• using, by the computer, the modified data in the blocks of the sparse object to update the existing object.

A computer program product comprising a computer readable storage medium having program instructions embodied therewith, wherein the computer readable storage medium is not a transitory signal per se, the program instructions readable and/or executable by a processor to cause the processor to perform a method comprising:

• sending, by the processor, a data access request;
• receiving, by the processor, a copy of an existing object which includes blocks, wherein data which corresponds to the data access request is stored in at least one of the blocks;
• capturing, by the processor, a snapshot of the received copy of the existing object;
• using, by the processor, the received copy of the existing object to perform a data operation;
• using, by the processor, the snapshot to determine ones of the blocks which include data that has been modified by the data operation;
• and
• sending, by the processor, a sparse object which only includes the ones of the blocks determined as including modified data.