1. A method for execution by a computing device, the method comprises: receiving a file creation request to create a new data file from portions of a set of existing files containing data, wherein an existing file of the set of existing files includes a plurality of data segments that is stored as a plurality of sets of encoded data slices in a dispersed storage network (DSN) memory; identifying, in accordance with the file creation request, data segments from the pluralities of data segments of the set of existing files corresponding to the portions of the set of existing files to produce identified data segments; identifying, based on the identified data segments, sets of encoded data slices of the pluralities of sets of encoded data slices of the identified data segments to produce identified sets of encoded data slices; determining addressing information for the identified sets of encoded data slices from existing addressing information of the set of existing files; and creating the new data file by generating a segment allocation table for the new data file based on the addressing information of the identified sets of encoded data slices such that the new data file is created without duplication of the portions of the existing files containing the data.