1. In a computer system including a host computer connected to a storage system having storage devices, a method of carrying out data movement operations comprising: receiving a data movement instruction, from an application program executing on the host computer, specifying a source data location in the storage devices and a destination data location in the storage devices; and transferring source data from the source data location to the destination data location at an operating system level of the host computer without transferring the source data between the application program and the operating system level.