A disk array subsystem including D disk apparatuses, wherein, there is a
redundancy of N (N is an integer equal to or larger than 3), the disk
array subsystem includes data regions of each of the disk apparatuses and
(N-1) copy regions on each of the disk apparatuses, first copies of data
to be stored in the data regions of each of the disk apparatuses are to
be distributedly arranged in first copy regions of each of the disk
apparatuses other than a disk apparatus from which the copies of data are
to be distributedly arranged, and second copies of data to be stored in
each of the first copy regions of each of the disk apparatuses are to be
distributedly arranged, with respect to each of the first copy regions of
each of the disk apparatuses, in second copy regions of each of the disk
apparatuses other than a disk apparatus from which the second copies of
data are to be distributedly arranged, and any of a disk apparatus that
any of original data of the second copies are to be stored in the data
region.