Patent ID: 7689796

Claim:
A computer system, comprising: a server; and a storage system, wherein: the server includes: an interface coupled to the storage system; a processor coupled to the interface; and a memory coupled to the processor; the storage system includes: a disk drive for storing data; and a controller for controlling the disk drive; the storage system manages a physical storage area of the disk drive for each one or more of physical blocks of predetermined sizes; the storage system manages allocation of one or more physical blocks to a plurality of logical blocks of predetermined sizes; the one or more physical blocks include at least one first physical block; the plurality of logical blocks include at least one first logical block and one or more second logical blocks; and the storage system stores data written in the first logical block in the first physical block allocated to the first logical block, and further allocates the first physical block to the second logical block in which the same data as that stored in the first physical block is to be written, wherein the server issues a request of further allocating the first physical block to the second logical block in order to write the same data as the data stored in the first physical block allocated to the first logical block in the second logical block; the storage system manages allocation of the physical block to the logical block for each allocation block constituted of a predetermined number of logical blocks; and the server obtains information indicating a size of the allocation block and information indicating a position of a head of the allocation block from the storage system, and issues the request of further allocating the first physical block to the second logical block based on the information obtained from the storage system.