Patent ID: 8984221
Filing Date: 2015-03-17
Classification: G06F

Abstract:
1. A computer system comprising a host computer on which at least one virtual machine is operated, a management server and a storage system mutually coupled to one another, wherein the storage system comprises a control unit, a cache memory unit, a shared memory unit, a physical memory device unit composed of multiple types of devices, and a virtual machine status management unit; the control unit is configured to generate multiple logical volumes to be assigned to the host computer; the physical memory device unit is composed of the multiple types of devices having a tier assigned to each type of devices; the logical volumes are mapped to the virtual machines; and the type of the physical memory device assigned to the logical volume mapped to the virtual machine is changed based on a status information of the virtual machine that the virtual machine status management unit acquires from the virtual machine, wherein the logical volumes are composed of a real volume, a first snapshot volume of the real volume, and a second snapshot volume of the first snapshot volume, wherein the real volume is mapped to the first snapshot volume and the first snapshot volume is mapped to the second snapshot volume, thereby adopting a cascading structure.