Apparatus and method for adopting an orphan I/O port in a redundant storage controller

摘要

A storage controller configured to adopt orphaned I/O ports is disclosed. The controller includes multiple field-replaceable units (FRUs) that plug into a backplane having local buses. At least two of the FRUs have microprocessors and memory for processing I/O requests received from host computers for accessing storage devices controlled by the controller. Other of the FRUs include I/O ports for receiving the requests from the hosts and bus bridges for bridging the I/O ports to the backplane local buses in such a manner that if one of the processing FRUs fails, the surviving processing FRU detects the failure and responsively adopts the I/O ports previously serviced by the failed FRU to service the subsequently received I/O requests on the adopted I/O ports. The I/O port FRUs also include I/O ports for transferring data with the storage devices that are also adopted by the surviving processing FRU.