Partial rebuild operation within a dispersed storage network including local memory and cloud-based alternative memory

A computer readable memory comprises:

• a first memory that stores operational instructions that, when executed by a rebuilding module within a device of a dispersed storage network (DSN), causes the rebuilding module to:
• detect an encoded data slice of a set of encoded data slices that requires rebuilding, wherein a data segment of a data object is dispersed storage error encoded into the set of encoded data slices, wherein a storage unit of the DSN includes a local memory and cloud-based alternative memory, wherein 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;
• a second memory that stores operational instructions that, when executed by the device of the DSN, causes the device to:
• determine whether to rebuild the encoded data slice using a full rebuild operation or partial rebuild operation;
• and
• when determined to rebuild the encoded data slice using the partial rebuild operation:
• send, by the rebuilding module, a partial rebuild request to the storage unit;
• and
• generate, by the storage unit, first partial rebuilding data based on the first encoded data slice and second partial rebuilding data based on the second encoded data slice;
• create, by the storage unit, a partial result by combining the first partial rebuilding data and the second partial rebuilding data;
• and
• create, by the rebuilding module, a rebuilt encoded data slice from the partial result and other partial rebuilding data from other storage units.