Patent ID: 7908434

Claim:
A redundant-arrays-of-independent-disks apparatus that temporarily stores a data block to be written to a magnetic disk apparatus in a cache, the redundant-arrays-of-independent-disks apparatus comprising: a cache managing unit that creates a list in which elements corresponding to each data block is arranged according to a priority for writing the data blocks temporarily stored in the cache to the magnetic disk apparatus, and when a group of consecutive elements corresponding to data blocks to be written to a same magnetic disk apparatus exists in the list, provides a link that connects elements at both ends of the group, each of the both ends of the group being arranged between the group and an element corresponding to a data block to be written to a different magnetic disk apparatus from the same magnetic disk apparatus; and a write control unit that searches, upon selecting a data block as a target for writing to the magnetic disk apparatus, the elements belonging to the list in descending order of priority, and if a link is set at an element corresponding to a data block of which a write destination is a magnetic disk that cannot perform a writing, follows the link to search a subsequent element.