Patent ID: 7801930

Claim:
A recording medium for storing data, and which is accessible to and detachable from a host, comprising: a data storage that stores various data; a host interface that communicates with the host; and a controller that controls the recording medium, wherein the data storage includes a data region for storing content data, and a retrieval information storing region for storing management information used by the host to acquire the content data, and the data storage further stores an open flag showing a possibility of inconsistency between information stored in the data region and information stored in the retrieval information storing region, and the controller updates the value of the open flag automatically to a value showing that there is the possibility of inconsistency, when receiving a write request or erase request to the data storage from the host, wherein, when the possibility of inconsistency is determined based on the open flag, the host verifies if an inconsistency actually exists between the information stored in the data region and the information stored in the retrieval information storing region of the detachable recording medium, and when an inconsistency is verified to actually exist, the host initiates an inconsistency correction function or does error handling.