A storage system includes a storage unit and a control unit. Data is stored in the storage unit. The control unit performs replication of data that is updated, based on the frequency with which the data is updated. The control unit may include a frequency detection unit, a policy management unit, and a replication performance unit. The frequency detection unit detects the update frequency with which the data is updated, by detecting the number of times that the data is updated. The policy management unit determines a replication policy for the data based on the update frequency with which the data is updated. The replication performance unit performs replication of the updated data based on the replication policy.