Provided is a computer system including at least one host computer; and at least one storage system, characterized in that: the storage system has a disk drive and a disk controller, and provides a storage area of the disk drive as at least one logical unit; upon detecting a failure in a logical path serving as an access route from the host computer to the logical unit, the host computer specifies logical paths for accessing the same logical unit that is connected to the logical path where the failure is detected; the host computer executes failure detecting processing for the specified logical paths to judge whether the specified logical paths are normal or not; the host computer selects normal logical paths out of the specified logical paths; and the host computer accesses the logical unit via the normal logical paths selected.