Patent ID: 8688932

Claim:
A server system comprising: a storage device including a plurality of disk volumes, a region of each of the disk volumes being allocated as a virtual disk; and at least one server device, each of which includes a plurality of virtual servers, each of which executes processing by using one of the allocated virtual disks, wherein the virtual disk used by a virtual server is divided into a plurality of logical blocks, and each of the logical blocks corresponds to a physical block, wherein each of the at least one server device comprises: a storing unit for storing information showing an erasing condition for each of the physical blocks; a specifying part for, after deleting a first virtual server among the virtual servers, specifying information for identifying the physical block of the virtual disk allocated to the first virtual server; an erasing part for erasing an erasing target physical block among the disk volumes based on the information identifying the specified physical block; and a usage part for using, by a second virtual server, the physical block allocated to the first virtual server, after completion of the erasing process of the physical block of the virtual disk allocated to the first virtual server among the virtual servers; and wherein when the server device does not recognize the disk volume to which the virtual disk for erasing the physical block is not allocated, making the server device to temporarily recognize the volume at a time of erasing of the physical block.