System, method, and computer program product for partitioned data replication are described. A data replication system can partition a file stored on a primary storage device into multiple data blocks, and store an index mapping the blocks and the file. Initially, the system can replicate the file and the index to a secondary storage device. The data stored in the file can change after the initial replication. The system can determine which block among the data blocks has changed by updating the index and comparing the updated index with the original index. The system can then replicate the change by replicating only the changed block and the updated index to the secondary system.