Data transfer method and system, input/output request device, and computer-readable recording medium having data transfer program recorded thereon

A data transfer system comprising:

• an external storage device equipped with a plurality of logic devices;
• an input/output request device for issuing an input/output request to each of said logic devices of said external storage devices;
• a plurality of paths which connects said external storage device to said input/output request device and which transfers data between said respective logic devices of said external storage device and said input/output request device;
• a priority level setting section for setting priority levels of said plurality of logic devices;
• a usage rate setting section for setting a distribution proportion at which the input/output requests to each said logic device are distributed to said plurality of paths on the basis of said priority levels such that each of said plurality of logic devices other than one of said plurality of logic devices with a lowest priority defined in terms of said priority levels uses two or more of said plurality of paths, and such that the logic device with the lowest priority uses only one of said plurality of paths which is different from two or more paths used by one of said plurality of logic devices with highest priority defined in terms of said priority levels to transfer the request to the logic device with the lowest priority;
• and
• a data transfer control section which performs said data transfer by using said respective paths according to the distribution proportions,
• wherein the distribution proportions are set such that total processing volumes of respective paths assigned to a logic device becomes larger as a priority level for the logic device becomes higher.

An input/output request device for transferring, through use of a plurality of paths, data to a plurality of logic devices provided in an external storage device by means of issuing input/output requests to each of said plurality of logic devices of said external storage device, the device comprising:

• a priority level setting section for setting priority levels of said plurality of logic devices;
• a usage rate setting section for setting a distribution proportion at which the input/output requests to each said logic device are distributed to said plurality of paths on the basis of said priority levels such that each of said plurality of logic devices other than one of said plurality of logic devices with a lowest priority defined in terms of said priority levels uses two or more of said plurality of paths, and such that the logic device with the lowest priority uses only one of said plurality of paths which is different from two or more paths used by one of said plurality of logic devices with highest priority defined in terms of said priority levels to transfer the request to the logic device with the lowest priority;
• and
• a data transfer control section which performs said data transfer by using said respective paths according to the distribution proportions,
• wherein the distribution proportions are set such that total processing volumes of respective paths assigned to a logic device becomes larger as a priority level for the logic device becomes higher.

A computer-readable recording medium having recorded thereon a data transfer program for causing a computer to fulfill a function for transferring, through use of a plurality of paths, data to a plurality of logic devices provided in an external storage device by means of issuing input/output requests to each of said plurality of logic devices of said external storage device, wherein

• said data transfer program causes said computer to act as:
• a priority level setting section for setting priority levels of said plurality of logic devices;
• a usage rate setting section for setting a distribution proportion at which the input/output requests to each said logic device are distributed to said plurality of paths on the basis of said priority levels such that each of said plurality of logic devices other than one of said plurality of logic devices with a lowest priority defined in terms of said priority levels uses two or more of said plurality of paths, and such that the logic device with the lowest priority uses only one of said plurality of paths which is different from two or more paths used by one of said plurality of logic devices with highest priority defined in terms of said priority levels to transfer the request to the logic device with the lowest priority;
• and
• a data transfer control section which performs said data transfer by using said respective paths according to the distribution proportions,
• wherein the distribution proportions are set such that total processing volumes of respective paths assigned to a logic device becomes larger as a priority level for the logic device becomes higher.