1. A method of accessing data in a dispersed storage network, the dispersed storage network including a plurality of primary dispersed storage units and a plurality of secondary dispersed storage units, the method comprising: dispersed storage error encoding a data segment to produce a set of encoded data slices; for each available primary dispersed storage unit of the plurality of primary dispersed storage units, sending a respective write slice request for receipt by a respective available primary dispersed storage unit, the respective write slice request including a respective slice name corresponding to the respective available primary dispersed storage unit and a respective encoded data slice of the set of encoded data slices, wherein the respective encoded data slice includes a first respective information dispersed algorithm index of the respective available primary dispersed storage unit; and for each unavailable primary dispersed storage unit of the plurality of primary dispersed storage units, sending a respective write imposter slice request for receipt by a respective secondary dispersed storage unit of the plurality of secondary dispersed storage units, the respective write imposter slice request including a respective imposter slice name corresponding to the respective secondary dispersed storage unit and a respective imposter encoded data slice of the set of encoded data slices, wherein the respective imposter encoded data slice includes a second respective information dispersed algorithm index of the respective unavailable primary dispersed storage unit.