Patent ID: 7254620
Filing Date: 2007-08-07
Classification: H04L

Abstract:
1. A storage system coupled to a plurality of host computers via a first network: wherein each of said host computers is operable to issue an input/output (I/O) request of data via said first network to said storage system on a logical volume basis, with routing information of the data being stored in a routing table in each of said host computers, a plurality of storage sub-systems storing data on a logical volume basis to be accessible by said host computers, and an arbitrator coupled to said storage sub-systems via a second network and to said host computers via said first network, wherein each of said plurality of host computers is provided with a network interface card (NIC) coupled to said first network, each of said plurality of storage sub-systems is provided with an NIC coupled to said first network, and said arbitrator is provided with an NIC coupled to said first network, wherein said arbitrator includes a logical volume transfer module and a routing information transmission module, wherein, when data of a logical volume stored in said first storage sub-system is to be transferred to said second storage sub-system, with said logical volume having an IP address and being accessed by a first host computer of said host computers, said logical volume transfer module instructs said first storage sub-system to transfer information as to said IP address of said logical volume to said second storage sub-system, said logical volume transfer module instructs said first and second storage sub-systems to transmit an IP datagram having said IP address as a destination address to said second storage sub-system, when receiving said IP datagram, said routing information transmission module instructs said first storage sub-system to transmit an ICMP Redirect Error message to said first host computer, when receiving an IP datagram having said IP address as a destination address from said first host computer, said routing information transmission module instructs said host computers to transmit updated routing information as to said logical volume, said first host computer updates an associated routing table according to contents of said ICMP Redirect Error message, when receiving said ICMP Redirect Error message, each of the host computers except said first host computer updates an associated routing table according to said updated routing information, and said logical volume transfer module instructs said first and second storage sub-systems to transfer said logical volume from said first storage sub-system to said second storage sub-system via said second network.