Reducing a size of backup data in storage

A computer program product for backing up data in a backup storage space, the computer program product comprising a computer readable storage medium having program code embodied therewith, the program code executable to:

• receive, by a computer, a request for backing up a second data file, the second data file created from a first data file;
• determine, by the computer, whether a third data file satisfies one or more of predetermined conditions for backup, the third data file generated when the second data file is created from the first data file, the third data file comprising information for creating the second data file from the first data file;
• and
• back up, by the computer, the third data file, without backing up the second data file, in response to determining that the third data file satisfies the one or more of the predetermined conditions for backup.

A computer system for backing up data in a backup storage space, the computer system comprising:

• one or more processors, one or more computer readable tangible storage devices, and program instructions stored on at least one of the one or more computer readable tangible storage devices for execution by at least one of the one or more processors, the program instructions executable to:
• receive, by a computer, a request for backing up a second data file, the second data file created from a first data file;
• determine, by the computer, whether a third data file satisfies one or more of predetermined conditions for backup, the third data file generated when the second data file is created from the first data file, the third data file comprising information for creating the second data file from the first data file;
• and
• back up, by the computer, the third data file, without backing up the second data file, in response to determining that the third data file satisfies the one or more of the predetermined conditions for backup.