A data transfer device is used to augment the capabilities of a data storage system. The data transfer device may be capable of persistently storing data for an indeterminate amount of time, and may be configured to store a portion of a bundle of redundancy coded shards that span between the data transfer device and a data storage system configured to store the remainder of the bundle. Data stored on the data transfer device may be read from and written directly to the data transfer device without transfer of data to the data storage system. If the data transfer device is not available, the remaining shards of the bundle may provide a regenerated, original form of the data.