A method begins by a processing module determining to move a range of encoded data slices from a first storage unit to a second storage unit of a plurality of storage units, where data objects are dispersed storage error encoded to produce pluralities of sets of encoded data slices, and where the pluralities of sets of encoded data slices are stored in the plurality of storage units. The method continues with the processing module transferring the range of encoded data slices from the first storage unit to the second storage unit. In response to the transferring the range of encoded data slices from the first storage unit to the second storage unit, the method continues with the processing module transferring a corresponding range of second encoded data slices from a third storage unit to a fourth storage unit.