Data back-ups are a critical task of any information technology department. Data back-ups are typically performed using some type of back-up tape systems. Internet based data storage systems now offer data storage services at low prices. To take advantage of such services, a system and method for efficiently back-up data volumes is disclosed. The data back-up system divides data volumes into fingerprinted data slices. Redundant data slices are then removed. Unique fingerprinted data slices are then copied to an internet based storage provider.