Patent ID: 9244849
Filing Date: 2016-01-26
CPC Classification: G06F

Claim Text:
1. A storage control apparatus for controlling to temporarily store an entirety of data transferred from a host in a cache disk in response to a write request from the host to a target logical volume among a plurality of logical volumes, and store the temporarily stored entirety of data in a storage apparatus in response to data transfer from the target logical volume to a physical volume corresponding to the target logical volume, the plurality of logical volumes being assigned with the cache disk, a plurality of logical volumes corresponding to the plurality of logical volumes being assigned with the storage apparatus, the storage control apparatus comprising: a memory configured to store access management information concerning access from the host to each of the plurality of logical volumes; and a controller configured to refer to the access management information read from the memory, when receiving an entirety of updated data from the host, to set a write mode for data transfer from each of the plurality of logical volumes to the corresponding physical volume on the basis of the access management information to one of a difference data write mode in which difference data indicating a difference between the entirety of data stored in the storage apparatus and the entirety of updated data is written into the storage apparatus and an entire data write mode in which the entirety of updated data is written into the storage apparatus, wherein the access management information includes access frequency information concerning frequency of access from the host to each of the logical volumes and data information concerning amount of data for each of the logical volumes, and the controller configured to: accumulate the amount of data for all the logical volumes in descending order of the frequency of access based on the access management information, determine whether the accumulated total amount of data for all the logical volumes exceeds a predetermined percentage of total capacity of the cache disk, when the accumulated total amount of data for all the logical volumes is equal to or less than the predetermined percentage of the total data capacity of the cache disk, set the difference data write mode as a write mode for data transfer of all the logical volumes, and when the accumulated total amount of data for all the logical volumes exceeds the predetermined percentage of the total storage capacity of the cache disk, set the difference data write mode as a write mode for data transfer of logical volumes corresponding to a part, among all the logical volumes, in which the amount of data of the logical volumes accumulated in descending order of the frequency of access is equal to or less than the predetermined percentage of the total storage capacity of the cache disk, and set the entire data write mode as a write mode for data transfer of logical volumes corresponding to a part, among all the logical volumes, in which the amount of data of the logical volumes accumulated in descending order of the frequency of access is exceeding the predetermined percentage of the total data capacity of the cache disk.