A cache controller controls data input/output of the storage device and causes the semiconductor storage device to function as a cache memory of the storage device. A staging controller performs, when data is staged from the storage device to the cache memory, first staging amount control until a staging amount to the cache memory exceeds a first threshold after the storage apparatus starts up; performs second staging amount control until a variation per unit time of a read amount from the cache memory falls within a predetermined range after the first period; and performs third staging amount control after the second period. With this configuration, the semiconductor apparatus can be efficiently used.
展开▼