A method, a computer program product, and a computer system for backing up data in a backup storage space. A computer receives a request for backing up a second data file, wherein the second data file is created from a first data file. The computer determines whether a third data file satisfies one or more of predetermined conditions for backup; wherein the third data file is generated when the second data file is created from the first data file and the third data file comprises information for creating the second data file from the first data file. In response to determining that the third data file satisfies the one or more of the predetermined conditions for backup, the computer backs up the third data file, without backing up the second data file.