1. A method for execution by one or more processing modules of one or more storage units (SUs) of a dispersed storage network (DSN), the method comprises: identifying, by a storage unit (SU) of the one or more SUs, a first storage format for a set of encoded data slices (EDSs) stored in a first DSN memory, wherein a data object is segmented into a plurality of data segments, and wherein a data segment of the plurality of data segments is dispersed error encoded in accordance with dispersed error encoding parameters to produce the set of encoded data slices (EDSs); determining to migrate the set of EDSs from the first storage format to a second storage format; selecting the second storage format for the set of EDSs; selecting a second DSN memory for the set of EDSs, wherein the second DSN memory is configured to store the set of EDSs based on the second storage format; determining a first migration rate to be used when migrating the set of EDSs from the first DSN memory to the second DSN memory; migrating a first subset of the set of EDSs from the first DSN memory to the second DSN memory based on the first migration rate to store the set of EDSs within the second DSN memory based on the second storage format; monitoring at least one of data access request activity or data access response activity associated with at least one of the first DSN memory or the second DSN memory; selecting a second migration rate based on the at least one of data access request activity or data access response activity associated with the at least one of the first DSN memory or the second DSN memory; and migrating a second subset of the set of EDSs from the first DSN memory to the second DSN memory based on the second migration rate.