A storage control system judges whether the data pattern of data exchanged with a higher-level device (hereafter "data") conforms to one or a plurality of write-excluded data patterns comprised in write-excluded data pattern information prepared in advance. If a negative judgment result is obtained, the storage control subsystem stores the data in a logical device formed on a disk storage device. If, on the other hand, a positive judgment result is obtained, the storage control subsystem erases the data without storing in a logical device.