An information processing system comprises an information processing
apparatus, a switch, and a storage device, wherein the first
communication ports and the third communication ports are connected to
the second communication ports. When a response from a storage device to
a data input/output request is not received within a predetermined time
period, the information processing apparatus transmits a second and a
third data input/output requests from the first communication port on the
first communication channel, and transmits an inspection request to the
switch to inspect a second communication port on the first communication
channel. When responses to the second and third data input/output
requests are not received within a predetermined time period, and a
response to the inspection request is received within a predetermined
time period, the information processing apparatus determines that there
is a fault in the first communication port on the first communication
channel.