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.