1. A method comprises: identifying, by a device of a dispersed storage network (DSN), an encoded data slice requiring rebuilding, wherein the encoded data slice is part of a set of encoded data slices produced by performing a dispersed storage error encoding function on a data segment; determining, by the device, whether the encoded data slice is part of a fan-out encoded data slice group in which one or more copies of the encoded data slice are stored in the DSN; when the encoded data slice is part of the fan-out encoded data slice group: determining, by the device, whether a valid encoded data slice of the fan-out encoded data slice group is available for retrieval from memory of the DSN; when a valid encoded data slice of the fan-out encoded data slice group is not available, rebuilding, by the device or another device, the encoded data slice to produce a rebuilt encoded data slice; storing, by a storage unit of the DSN, the rebuilt encoded data slice; and creating, by the storage unit, one or more copies of the rebuilt encoded data slice to produce a rebuilt fan-out encoded data slice group.