According to one embodiment, a wearable electronic device includes communication circuitry configured to communicate with an external device, and transmit access right information to the external device, the access right information for a write access right to first data stored in a server, the first data corresponding to a user of the electronic device. The prime mover is either an electric motor or an internal combustion engine, advantageously a diesel engine. The memory also includes a controller that determines whether to select a garbage collection unit of the multiple garbage collection units for garbage collection based on a variable threshold number of the multiple garbage collection units to garbage collect.