DATA MOVING METHOD BETWEEN SUBSYSTEMS

摘要

PROBLEM TO BE SOLVED: To move data between new and old subsystems with non-stop. SOLUTION: Plural first access routes 20 and 21 are prepared from a CPU 10 to an old CU (old subsystem) 13 having an old VOL 14 under control and plural third access routes 30 and 31 are set to a new CU (new subsystem) 11 having a new VOL 12 under control. Then, the connection is changed while being divided plural times from the first access routes 20 and 21, of the old subsystem as moving source to second access routes 20' and 21' of the new subsystem as moving destination. When the new subsystem receives access through the second access routes 20' and 21' on the side of the new subsystem from the CPU 10 during the connection change, a bus move control part 11 repeats the relevant access through the third access routes 30 and 31 to the side of the old subsystem and processes it. The move of data from new to old subsystem is executed after all the first access routes are switched to the second access routes.