Patent ID: 7370228

Claim:
A data processing system comprising: a plurality of disk array devices each including a storage device in which a plurality of logical volumes for storing data are set and a controlling unit for controlling storage of data into the logical volumes set in said storage device, wherein said plurality of disk array devices include at least a first disk array device, a second disk array device, and a third disk array device, said first disk array device being disposed at a first site, said second disk array device being disposed at a second site, and said third disk array device being disposed at a third site, wherein said first disk array device includes a first logical volume, said second disk array device includes a second logical volume and a third logical volume, and said third disk array device includes a fourth logical volume and a fifth logical volume, wherein said data processing system is capable of bidirectional data transfer among said first disk array device, said second disk array device, and said third disk array device, wherein a controlling unit of said first disk array device includes a function of, upon reception of a command having a remote command function issued from a host apparatus connected to said first disk array device, analyzing the command, transferring the command to said second disk array device when an instruction command for remote transfer to said second disk array device is added, and performing a process within said first disk array device when it is not added, wherein a controlling unit of said second disk array device includes a function of, upon receipt of the command having the remote command function transferred from said first disk array device, analyzing the command to transfer the command to said third disk array device when an instruction command for remote transfer to said third disk array device is added, and performing a process within said second disk array device when it is not added, wherein a controlling unit of said third disk array device has a function of, upon receipt of the command having the remote command function transferred from said second disk array device, performing a process within said third disk array device, and wherein the command having said remote command function includes a first control command to said first disk array device for synchronous remote copying, a second control command to said second disk array device for asynchronous remote copying, a third control command to said second disk array device for a replica function, and a fourth control command to said third disk array device for the replica function.