DFSMSdss uses virtual concurrent copy (VCC) to provide a concurrent copy-like function when the source device supports data set FlashCopy® or SnapShot.

During virtual concurrent copy, data is "flashed" or “snapped” from the source location to an intermediate location, and the data is gradually copied to the target location through standard I/O methods. The operation is logically complete after the source data is "flashed" or “snapped” to the intermediate location and physically complete after the data is moved to the target media.

The working space data set is used as an intermediate location for virtual concurrent copy. For more information, see Virtual concurrent copy working space.