Patent ID: 8131783

Claim:
A storage system, comprising: a storage apparatus; a plurality of file management computers building file systems on volumes in the storage apparatus; and a management computer managing and redistributing allocated capacity of the volume allocated to the respective file systems, wherein the management computer stores file system statistical information and storage apparatus statistical information, both of which are collected from the file management computers and the storage apparatus, wherein the file system statistical information relates to the allocated capacity for each of the file systems, wherein the storage apparatus statistical information relates to volume capacity of the storage apparatus, wherein the management computer calculates the allocated capacity to the respective file systems so that total available capacity for the file systems satisfies predetermined performance information, based on the file system statistical information and the storage apparatus statistical information, when the management computer accepts a redistributing request for the allocated capacity for the file system, wherein the management computer transmits a file system reducing instruction to the file management computer which is among the plurality of the file management computers and manages the file system whose allocated capacity is to be reduced, wherein the management computer transmits a volume capacity changing instruction to the storage apparatus based on the allocated capacity, wherein the management computer transmits a file system expanding instruction to the file management computer which is among the plurality of the file management computers and manages the file system whose allocated capacity is to be expanded, wherein the file system statistical information comprises identification data (ID) of the file system; identification data (ID) of the volume; the allocated capacity of the volume; the available capacity of the volume; and a capacity consuming speed which is the speed consuming the capacity, and wherein the storage apparatus statistical information comprises the identification data (ID) of the volume, the allocated capacity for the respective identification data (IDs) of the volumes, and wherein the predetermined performance information is the capacity consuming speed.