A storage device configured to be connectable to a host device, the storage device:
- comprising:
- a storage element configured to include a first storage area managed by a first file system and a second storage area managed by a second file system;
- a first register configured to retain information on a storage capacity of the first storage area;
- a second register configured to retain information on a storage capacity exceeding the storage capacity of the first storage area;
- and
- a controller configured to control the storage element, wherein the controller receives an initialization command from the host device.