Patent ID: 8069301

Claim:
A data control apparatus comprising: a mapping-table managing unit that manages a mapping table that is contained arrangement information of data and error correcting code data as redundant data that is given separately from the data, distributed and stored in units of stripe blocks in a plurality of nonvolatile semiconductor memory devices; a determining unit that determines whether to differentiate frequencies of writing the data into the semiconductor memory devices; and a changing unit that changes the arrangement information by switching the data stored in units of the stripe blocks managed using the mapping table to differentiate the frequencies of writing the data into the semiconductor memory devices, when the determining unit determines that the frequencies of writing the data into the semiconductor memory devices are to be differentiated, wherein when a difference in life expectancy between top two of the semiconductor memory devices having shorter life expectancies becomes lower than a predetermined threshold value, the changing unit changes the arrangement information by switching the data stored in units of the stripe blocks managed using the mapping table to differentiate the frequencies of writing into the top two semiconductor memory devices having shorter life expectancies.