Patent ID: 7565474

Claim:
A computer system, comprising: a plurality of CPU units; a serial connect switch unit having at least three ports and for interconnecting each CPU unit being connected to each port by a serial connect bus, said serial connect switch having one of said at least three ports being set as an upstream port for connecting an upstream device that executes link establishment with each of said CPU units connected to said ports except the upstream port; a management controller judging link establishment of the upstream port, and when judging that the link establishment fails, executing said link establishment with each of said CPU units connected to said ports except the upstream port as said upstream device of the serial connect switch; and a switch circuit switching the upstream port of the serial connect switch to either one of the manager controller and said upstream device, wherein said manager controller switches the switch circuit so as to connect the upstream port of the serial connect switch to the manager controller when judging that link establishment fails.