1. A method comprising: determining a slice name of an encoded slice to be rebuilt within a first dispersed storage network (DSN); determining that the first DSN and a second DSN are each storing an encoded copy of a data file; determining that the first and second DSNs utilizes a different set of error coding dispersal storage parameters but similar decoding thresholds to produce the encoded copy of the data file that includes a plurality of sets of encoded slices; determining whether the encoded slice is an encoded data slice or an encoded parity slice of the plurality of sets of encoded slices; when the encoded slice is the encoded data slice, retrieving a corresponding copy of an encoded data slice from the second DSN as a corresponding copy of the encoded slice; and storing the corresponding copy of the encoded slice as a rebuilt encoded slice within the first DSN.