Method for reducing primary and backup storage

Abstract

A system and method identifies target device file matches of a source file based on file size and hash values. The method includes storing a first source file hash value of the first source file, wherein the first source file hash value was generated by applying a hash function to the first source file, appending a first source file size to the first source file hash value to generate a first appended source file hash value, scanning a target file dataset comprising N target files, wherein the target file dataset is on a target device. Scanning includes determining a respective file size for each of the N target files in the target dataset, determining whether each of the N target files is a size-matching target file, wherein a size-matching target file is any target file of the N target files that matches the first source file size, and generating a respective target file hash value for each size-matching target file by applying the hash function to each size-matching target file.