Patent ID: 7155636

Claim:
A fault detecting method on a data path between two disk storage devices among a plurality of disk storage devices interconnected through a communication line, comprising: obtaining a selected fault detection test from a group of tests comprising a first fault detection test, a second fault detection test, and a third fault detection test; performing data transfer operations over a data path between a first disk storage device and a second disk storage device in accordance with said selected fault detection test; detecting a fault in said data path based on a result of said data transfer; signaling an indication of said fault in order to initiate a repair action; and resuming normal data transfer by using said data path at a time subsequent to said repair actions, wherein said first fault detection test comprises steps of: performing a read operation wherein data on said first disk storage device is read therefrom and stored to said second disk storage device; and performing a write operation wherein data stored on said second disk storage device is read therefrom and stored to said first disk storage device, wherein said second fault detection test comprises steps of: generating random data; storing said random data in said first disk storage device; and transferring said random data from said first disk storage device to said second disk storage device, wherein said first and second disk storage devices each comprises a plurality of disk drives and said third fault detection test comprises steps of: designating a disk drive in said first disk storage device as a first fault detection drive; designating a disk drive in said second disk storage device as a second fault detection drive; and reading out data stored in said first fault detection drive and storing said data onto said second fault detection drive.