A control device for a non-volatile memory express (NVMe) over fabric architecture is provided. The control device comprises a network adapter and a processor coupled to the network adapter by a bus. Data is transmitted between the control device and a storage device in the NVMe over fabric architecture. The processor is configured to obtain an available storage space of the storage device, determine whether a storage space required by a first data to be transmitted according to a first data read/write command is equal to or less than the available storage space, and send the first data read/write command to the storage device if the storage space required by the first data is equal or less than to the available storage space and suspend sending of the first data read/write command if the storage space occupied by the first data is greater than the available storage space.