The method of allocating memory space

The present invention provides a method for allocating storage space, comprising: a user during a write operation, when the limited physical storage space is insufficient, the physical extents find available storage space from the shared physical data and writing the free physical extents ; and the user is assigned an extended physical storage space, the data is transferred to the extended physical storage space. Therefore, to improve the utilization of storage space, reducing the need for storage space, thereby reducing the cost.