DISK ARRAY SYSTEM HAVING ON-LINE BACKUP FUNCTION

摘要

PROBLEM TO BE SOLVED: To perform on-line backup of mass disk data while securing data consistency between starting backup and ending it. SOLUTION: In this disk array system 10, a cache memory 16 for temporal storage of data that is subjected to disk access and a freeze setting part 173 which is provided in a controlling part 17 and fixes data in an area with a designated disk area including a backup object disk area, e.g. a disk array 11 as write stop in response to a freeze command from a host device 20. Updated to be written in the memory 16 in response to a write request to the applicable disk area during backup processing from the backup object disk area undergoing freeze setting to a backup device 12 are returned to a prescribed disk area after backup processing is completed and a freeze set disk array 11 undergoes freeze release.