In a storage system including a plurality of nodes that provide a storage area and a drive that physically stores data, a parity group is configured with a plurality of data including user data stored in the storage area and redundant data for protecting the user data, a plurality of data in the parity group are stored in a storage area within one predetermined range across a plurality of nodes, and processing for dividing the predetermined range or processing for merging a plurality of predetermined ranges is performed based on a state of the predetermined range.