1. A method for execution by a processing module of a computing device, the method comprises: identifying a plurality of dispersed storage networks (DSNs) for storing copies of dispersed storage encoded data based on global data retrieval accesses of the copies of the dispersed storage encoded data, wherein a DSN of the plurality of DSN includes a plurality of dispersed storage units, wherein each dispersed storage unit of the plurality of dispersed storage units includes a plurality of memory devices; determining a set of local error coding dispersal storage parameters for a local DSN of the plurality of DSNs based on local data retrieval accesses allocated to the at least one of the plurality of DSNs; determining a set of global error coding dispersal storage parameters for at least one other of the plurality of DSNs based on the global data retrieval accesses of the copies of the dispersed storage encoded data; encoding data in accordance with the set of local error coding dispersal storage parameters to produce a local copy of the copies of the dispersed storage encoded data; encoding the data in accordance with the set of global error coding dispersal storage parameters to produce a global copy of the copies of the dispersed storage encoded data; outputting the local copy of the copies of the dispersed storage encoded data for storage within the local DSN of the plurality of DSNs; and outputting the global copy of the copies of the dispersed storage encoded data for storage within the at least one other of the plurality of DSNs.