For a full or tracks copy operation, DFSMSdss serializes the VTOC to preclude DADSM functions (such as ALLOCATE, EXTEND, RENAME, and SCRATCH) from changing the contents of the VTOC on the volume during the copy operation. Data sets are not serialized on these full or tracks operations. Therefore, some data sets might be opened by other jobs during the copy, resulting in copies of partially updated data sets. You can minimize this possibility by performing the copy when there is low system activity.

Full data integrity can only be guaranteed by performing copy operations by data set when TOL(ENQF) or SHARE are not specified.