US Patent 7606129 Disk controlling apparatus and computer product

A disk apparatus writes and rewrites data in a storage disk and reads data from the storage disk. A disk controlling apparatus that controls the disk apparatus includes an environment information creating unit creates environment information that is related to an environment of the disk apparatus, a storing unit that appends the environment information to the data that is to be written to the storage disk, and a rewrite process determining unit determines whether to execute a rewrite process based on the environment information in the data read from the storage disk.