Patent ID: 8533417

Claim:
A storage system comprising: a processor; a memory; and a plurality of chunks that are to be allocated to data volumes, each chunk having one or more data blocks; wherein the plurality of chunks include zero or more used chunks which are allocated to one or more data volumes, and zero or more remaining chunks which are not used chunks; wherein the processor is configured to manage the data volumes to which one or more chunks is allocated in response to write access, and to manage a total number of used chunks which have been allocated to one or more data volumes and a total number of reserved chunks which are reserved for use in the one or more data volumes but have not been allocated to any data volume; wherein the processor is configured to control data volume creation of data volumes; and wherein if the processor receives a new data volume creation request with a number of reserved chunks for a new data volume, the processor prohibits or warns against the new data volume creation request before the new data volume is created, based on the managed total number of the used chunks and the managed total number of the reserved chunks and the number of reserved chunks for the new data volume.