Patent ID: 8738829

Claim:
An information system comprising: a system board having a first bus bridge device and a second bus bridge device; an active I/O board having multiple I/O bus bridge devices, which includes an I/O bus bridge device connected via a bus to the first bus bridge device of the system board; a standby I/O board, for being used in place of the active I/O board when the active I/O board fails, having multiple I/O bus bridge devices, which includes an I/O bus bridge device connected via a bus to the second bus bridge device of the system board; and a configuration controller board being connected to the system board, the active I/O board and the standby board via respective control buses, and having a capability to perform an I/O board replacement process that sets the downstream side logical bus number set in the first bus bridge device into the second bus bridge device after stopping operation of the first bus bridge device, and then sets each logical bus number set in each I/O bus bridge device of the active I/O board into corresponding I/O bus bridge device of the standby I/O.