Storage system and data arrangement method of storage system

A data arrangement method in a storage system including a plurality of nodes that process an I/O processing request of data, wherein

• each of the plurality of nodes includes:
• a storage device;
• and
• a processor configured to:
• perform the I/O processing on the storage device;
• use a data redundancy configuration in which data stored in different storage devices is combined as a data set;
• perform 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 one of a node and the storage device, and by using data redundancy configuration information related to the data redundancy configuration
• determine a data arrangement by applying the data redundancy configuration related to the calculated fault tolerance information,
• wherein the fault tolerance information related to the data redundancy configuration includes a number of components having operational continuity in a case where a failure occurs for each of plurality of component types, and the data arrangement, to which the data redundancy configuration is applied, is determined such that the number of components having operational continuity satisfies a predetermined reference in a case where the failure occurs for each of the plurality of component types.