Patent ID: 8909825

Claim:
A storage device connectable to another storage device via one or more communication lines, the storage device comprising: a point value calculator that calculates a first-point value representing whether a transfer state of data forwarded from the storage device via the communication lines is good; a notifier that notifies the first point value to the another storage device; a receiver that receives a second point value representing whether a transfer state of data forwarded from the another storage device via the communication lines are good, the second point value being calculated by the point value calculator included in the another storage device; a multiplicity calculator that calculates, using the first point value and the second point value, a multiplicity representing number of data transfer processes which the storage device is able to simultaneously carry out on the communication lines; and a forwarding controller that forwards data via the communication lines within the calculated multiplicity, wherein the multiplicity calculator calculates a rate of the first point value to the sum of the first point value and the second point value, and calculates the multiplicity by multiplying a maximum multiplicity set for the communication lines and the calculated rate.