Patent ID: 7656789

Claim:
A method for providing redundant I/O access between a plurality of interconnected processor nodes and I/O resources, the method comprising: determining whether a primary path between the interconnected processor nodes and the I/O resources is operational, the primary path including a first processor node, and a primary multiplexer, wherein the primary multiplexer is attached to the I/O resources, and the primary multiplexer includes a primary link port; routing transactions via the primary path in response to determining that the primary path is operational; routing the transactions between the interconnected processor nodes and the I/O resources attached to the primary multiplexer via an alternate path in response to determining that the primary path is not operational, the alternate path including a second processor node and an alternate multiplexer, wherein the alternate multiplexer includes an alternate link port connected to the primary link port via an alternate link, and the second processor node accesses the I/O resources attached to the primary multiplexer via the alternate multiplexer through the alternate link; and transmitting idle sequence traffic on the alternate link on a continuous basis while the primary path is operational in routing the transactions in a normal mode of operation, the idle sequence traffic verifying availability of the alternate link prior to routing the transactions via the alternate path.