Patent ID: 7496717

Claim:
A method for sharing a storage device among controllers in a system, wherein said system comprises a first controller, a second controller and a storage device, said first controller, said second controller and said storage device are coupled together, and said storage device has a plurality of storage units each having a unique identification number, comprising steps of; enabling said first controller to detect the presence of said storage units and obtain access paths of said storage units via said storage device according to said identification numbers respectively; enabling said second controller to detect the presence of said storage units and obtain access paths of said storage units via said storage device according to said identification numbers respectively; enabling one of said controllers to define said storage units accessible by the other controller as virtual storage units each having a unique virtual identification number different from the identification number thereof, and calculate said virtual identification number by using a base number and said identification number corresponding thereto; enabling said one controller to request the other controller to perform data access to one of said storage units corresponding to said virtual identification number; enabling the other controller to identify said storage unit having an identification number corresponding to said virtual identification number; and enabling the other controller to perform data access to said identified storage unit and transmitting said data obtained from said storage unit corresponding to said virtual identification number to said first controller.