Patent attributes
In a multi-node storage system, a node's capacity has an upper limit, and capacities provided by nodes are smaller than a capacity of a global pool. A volume having a capacity larger than the capacity of one node is created by the node. A write error occurs when an amount of data larger than the capacity of the node is written. A storage system reduces the frequency of such a write error. A global pool is based on a plurality of local pools of a plurality of storage nodes that constitute a node group. In any of the storage nodes, a capacity relationship is maintained where a used capacity of a volume created by the storage node is equal to or less than an available capacity of a local pool of the storage node. A storage management unit manages the node group and selects the storage node.
