A method includes detecting an encoded data slice of a set of encoded data slices that requires rebuilding. A storage unit of the DSN includes a local memory and cloud-based alternative memory. The storage unit stores at least one of first and second encoded data slices of the set of encoded data slices in the cloud-based alternative memory. The method further includes determining whether to rebuild the encoded data slice using a full rebuild operation or partial rebuild operation. When determined to rebuild the encoded data slice using the partial rebuild operation, a partial rebuild request is sent to the storage unit. The storage unit then generates partial rebuilding data based on the first and second encoded data slices. The rebuilding module then creates a rebuilt encoded data slice from the partial rebuilding data and other partial rebuilding data from other storage units.