A method begins by a dispersed storage (DS) processing detecting unavailability of a storage device of a site of dispersed storage network (DSN) memory to produce an unavailable storage device. The method continues with the DS processing module reassigning a fraction of a logical address sub-range of the unavailable storage device to one or more other storage devices, rebuilding one or more logically addressable data objects to produce one or more rebuilt data objects and storing the one or more rebuilt data objects in the one or more other storage devices. When the unavailable storage device becomes available, the method continues with the DS processing module reallocating the fraction of the logical address sub-range from the one or more other storage devices to the storage device and transferring the one or more rebuilt data objects from the one or more other storage devices to the storage device.