Patent ID: 8407527

Claim:
A method for use in diagnosing hardware faults in a data storage system, such method comprising: receiving user I/O errors; reading disk drive port error counters associated with a disk drive port, primary port error counters associated with a primary port and expansion port error counters associated with an expansion port, wherein the disk drive port is coupled to a link control card, wherein the link control card is coupled to the primary port and the expansion port, wherein the disk drive port error counters indicate a fault in a disk drive coupled with the disk drive port, wherein the primary port error counters and expansion port error counters indicate a fault in the link control card; comparing the disk drive port error counters with the primary port error counters and expansion port error counters; based on the comparison, determining a type of the fault; and based on the type of the fault, modifying a user I/O error threshold.