Patent ID: 6813683
Filing Date: 2004-11-02
Classification: G06F

Abstract:
A system comprising:a master disk subsystem having a controller that communicates data with a host unit, a storage device that stores the data, and a control function that transfers and interrupts the transfer of the data to a first remote disk subsystem, at a predetermined interval; a slave disk subsystem having a controller that communicates data with the host unit, a storage device that stores the data, a transmission channel connected to the master disk subsystem, an inquiry detector that determines whether the master disk subsystem is in a data transfer state or in an interrupted data transfer state, the slave disk subsystem transferring the data to a second remote disk subsystem when the master disk subsystem is in the data transfer state; the first remote disk subsystem having a controller that receives data transferred from the master disk subsystem, and a storage device that stores the data; and the second remote disk subsystem having a controller that receives data transferred from the slave disk subsystem, and a storage device that stores the data.