This computer system includes a plurality of nodes for forming a distributed KVS. The plurality of nodes have a plurality of key ranges to which upper-limit data amounts are set, each upper-limit data amounts being an upper limit of an amount of manageable data. When a new key range is created, the plurality of nodes lowers an upper-limit data amount of an existing key range so that the sum of an upper-limit data amount of the new key range and an upper-limit data amount of the existing key range does not exceed a maximum amount which is the amount based on the volume of the memory of the computer apparatus.