1. A method for execution by a processing module in a distributed storage (DS) unit, the method comprising: receiving a request to retrieve an error coded (EC) data slice from a user device, wherein data segment is dispersed error encoded to produce a plurality of EC data slices that includes the EC data slice; determining whether the EC data slice is sub-sliced into a plurality of EC data sub-slices based on information stored within the DS unit; when the EC data slice is determined to be sub-sliced: identifying storage locations of the plurality of EC data sub-slices within other DS units; transmitting retrieval commands for the plurality of EC data sub-slices to the other DS units; receiving, in response to at least some of the retrieval commands, a minimum number of EC data sub-slices required to reconstruct the EC data slice; and reconstructing the EC data slice from the minimum number of EC data sub-slices; when the EC data slice is determined not to be sub-sliced, retrieving the EC data slice from local memory of the DS unit; and outputting the EC data slice or the reconstructed EC data slice, via a network interface of the DS unit.