Patent ID: 8543786

Claim:
A computer system, comprising: multiple storage control apparatuses configured to create at least one virtual logical volume; at least one host computer configured to use the virtual logical volume; and at least one management computer for managing the respective storage control apparatuses and the host computer, wherein each of the storage control apparatuses is configured to allocate a real storage area of a real volume inside a pool to the virtual logical volume in response to a write access from the host computer, and to store write data received from the host computer in the allocated real storage area, wherein the management computer comprises: a microprocessor configured to read and execute a prescribed computer program; a memory for storing the prescribed computer program; and a communication interface part for communicating with the respective storage control apparatuses and the host computer, wherein the microprocessor, by reading and executing the prescribed computer program, is configured to: acquire a utilization status of each of the pools; determine, based on the acquired utilization status of each of the pools, whether or not there exists a prescribed pool that requires pool size expansion; when the prescribed pool is detected, select, based on a prescribed selection criterion, a volume addition method for adding an unused real volume to the prescribed pool; and expand a pool size of the prescribed pool in accordance with the selected method.