In an information system, for I/O migration, the migration management module detects a first I/O function associated with a first I/O device to which the OS is connected, selects a second I/O function associated with a second I/O device which is the same type of the first I/O device, and instructs to hot-add the second I/O function to the OS. And the OS sets a teaming for a first virtual MAC address of a first virtual NIC corresponding to the first I/O function and a second virtual MAC address of a second virtual NIC corresponding to the second I/O function, and disconnects the first virtual MAC address of the first virtual NIC corresponding to the first I/O function.