A data storage system for storing data includes a data storage medium and a data interface that communicates with the data storage medium. The data interface is configured to place data into a logical data capsule having a defined size, where the data placed into the logical data capsule can occupy less than the defined size of the logical data capsule. In the data storage system, the logical data capsule is moved as a whole between the data storage medium and the data interface. Additionally, when any data in the logical data capsule is read or modified, all of the data in the logical data capsule is read or modified as a whole.