Methods and apparatus for accessing dispersed storage error encoded data in a dispersed storage network (DSN). For each available primary storage unit, a processing module issues a write slice request including a slice name and encoded data slice corresponding to the primary storage unit where the encoded data slice includes an information dispersal algorithm (IDA) index of the primary storage unit. For each unavailable primary storage unit, the processing module issues a write imposter slice request to a foster storage unit that includes a slice name corresponding to foster storage unit and an imposter encoded data slice corresponding to the unavailable primary storage unit, where the imposter encoded data slice includes an IDA index corresponding to the unavailable primary storage unit. When the unavailable primary storage unit becomes available, the processing module facilitates transfer of the imposter encoded data slice to the newly available primary storage unit.