Patent ID: 7773589
Filing Date: 2010-08-10
Classification: G06F,H04L

Abstract:
1. A storage system which is connected to a host computer, the storage system comprising: a plurality of nodes; and a plurality of disk drives connected to the nodes, each node having: a host interface unit which is connected to the host computer to communicate with the host computer, a drive interface unit which is connected to the disk drives to access to the disk drives, and a switch which communicates with the host interface unit and the drive interface unit, wherein the switch is connected to the switches in the other nodes, such that the nodes are connected to one another in a two-dimensional lattice shape, wherein the respective disk drives are connected to two drive interface units provided in different nodes, wherein the node has a two-dimensional address which is indicative of a position of the node in the two-dimensional lattice shape in which the nodes are connected to one another, wherein each node: transmits and receives a packet, which includes at least an address of a destination node, a detour mark, a reverse search mark, and a search count, with other nodes, when receiving the packet, compares the address of its own to the address of the destination node included in the received packet, when the address of the node does not match with the address of the destination node, determines an adjacent node which is positioned on a shortest path from the node to the destination node, when two adjacent nodes which are positioned on two different shortest paths respectively are determined, compares traffic amounts of the two determined adjacent nodes to each other, transmits the packet to one adjacent node having a smaller traffic amount of the two determined adjacent nodes, when the transmission fails, transmits the packet to the other adjacent node of the two determined adjacent nodes, when only one adjacent node which is positioned on the shortest path is determined, transmits the packet to the determined adjacent node, when the transmission fails, judges whether or not the destination node is adjacent to the node, if it is judged that the destination node is not adjacent to the node, sets the detour mark to valid and determines two adjacent nodes which are positioned on two different second shortest paths from the node to the destination node respectively, compares the traffic amounts of the determined adjacent nodes which are positioned on the second shortest paths one another, transmits the packet to the one adjacent node having the smaller traffic amount which is positioned on the one second shortest path, when the transmission fails, transmits the packet to the other adjacent node which is positioned on the other second shortest path, the adjacent node which receives the packet having a valid detour mark does not transmit the packet to the node which transmits the packet, if it is judged that the destination node is adjacent to the node, when the reverse search mark is invalid, increments the search count by 1 and transmits the packet to the node in a predetermined first direction, when the transmission fails, sets the reverse search mark to valid, sets the search count to 1, and transmits the packet to the node in a predetermined second direction, if it is judged that the destination node is adjacent to the node, when the reverse search mark is valid, increments the search count by 1 and transmits the packet to the node in the predetermined second direction, and when the reverse search mark is valid and the transmission fails, or when the search count exceeds 8, reports a fault.