ARBITRATION MONITORING FOR SERIAL ATTACHED SMALL COMPUTER SYSTEM INTERFACE SYSTEMS DURING DISCOVERY

Methods and structure for detecting that arbitration is delaying discovery. One embodiment is a Serial Attached Small Computer System Interface (SAS) expander. The SAS expander includes multiple SAS ports, a port monitor, and a controller. The port monitor is able to track physical link events during arbitration for at least one of the ports while discovery is in progress at the expander, and to detect based on the physical link events that arbitration is delaying discovery. The controller is able to prioritize discovery requests at the expander responsive to detecting that arbitration is delaying discovery.