A control device including a processor. The processor configured to allocate a data area of a memory device to a plurality of memory areas of data blocks of a first size; allocate identical data blocks of the first size to a plurality of the data areas of the memory device; manage management information indicating a data storing state of the plurality of memory areas of data blocks of the first size in each data area; determine, based on the management information regarding a plurality of data areas allocated with respect to a data block to be written, one data area from the plurality of data areas; and generate write data of a second size, which is different from the first size, including data of the data block to be written and write the write data in the one data area.