A method begins by a dispersed storage (DS) processing module receiving a file creation request to create a new file from portions of a set of existing files. The method continues with the DS processing module identifying data segments associated with the set of existing files corresponding to the portions of the set of existing files to produce identified data segments and identifying sets of encoded data slices of the identified data segments to produce identified sets of encoded data slices. The method continues with the DS processing module determining addressing information for the identified sets of encoded data slices from existing addressing information of the set of existing files and generating a segment allocation table for the new file based on the addressing information of the identified sets of encoded data slices such that the new file is created without duplication of the portions of the existing files.