A method begins by a dispersed storage (DS) processing module dividing a very large data object into a plurality of data regions and generating a data object storage tracking table that includes sections for identifying one or more data regions that are available or unavailable for retrieval. The method continues with the DS processing module dividing a first data region into data segments and disperse storage error encoding the data segments to produce sets of encoded data slices. The method continues with the DS processing module sending DSN write requests regarding storing the sets of encoded data slices to storage units and when at least a write threshold number of write responses is received for each of the sets of encoded data slices, updating the data object storage tracking table to indicate that the first data region is available for retrieval.