Storage devices herein include a non-volatile memory and a controller configured to perform a read operation on a physical page of the non-volatile memory in response to a read request on a logical page of the non-volatile memory from a host. The controller may include a mapping manager configured to manage a plurality of logical blocks by a logical unit. The mapping manager may include a unit map table including a correlation between the logical unit and a physical unit corresponding to the logical unit. Additionally, the mapping manager may be configured to change a mapping method according to whether the unit map table includes a physical unit corresponding to a logical unit including a logical page requested by the host. Related user devices and electronic devices are also provided.