An object is to construct a storage system with a configuration with a high degree of freedom while ensuring a certain fault tolerance. The storage system includes a plurality of nodes that process an I/O processing request of data. The node has a storage device and a processor that performs the I/O processing on the storage device. The processor constitutes a data redundancy configuration in which data stored in different storage devices is combined as a data set. A management unit for managing the storage system performs a fault tolerance calculation of calculating fault tolerance information for a failure of each component by using component information that is information of a component including at least the and the storage device, and by using data redundancy configuration information related to the data redundancy configuration, and determines a data arrangement by applying the data redundancy configuration related to the calculated fault tolerance information.