Patent ID: 9436559
Filing Date: 2016-09-06
CPC Classification: G06F

Claim Text:
1. A storage apparatus that is connected to a host apparatus, the storage apparatus comprising: a memory that includes a save memory area and a cache memory area which temporarily stores data received from the host apparatus; a storage device that stores the data; and a processor, wherein the processor: controls a duplication process for specified data into an other storage apparatus at a point in time of a start of duplication, increments a checkpoint number when data blocks are reflected from the memory to the storage device, creates a first checkpoint list, wherein the checkpoint list includes a first list of data blocks and first checkpoint numbers that correspond to most recent data in the cache memory area, creates a second checkpoint list, wherein the checkpoint list includes a second list of data blocks and second checkpoint numbers that correspond to when data was reflected to the save memory area, saves, based on a comparison of the first checkpoint list and the second checkpoint list, a first data block into the save memory area when receiving an update request of the first data block in the cache memory area after the start of duplication, updates the first data block in the cache memory area to an updated data block, reads the first data block from the save memory area, and transmits the first data block to the other storage apparatus.