A Dynamic Storage Subsystem Morphing (DSSM) mechanism (40) is connected to a plurality of storage subsystem resources, which reserve some storage area each non-donor ECU (12), ready for a "slot-down/up" access by a respective non-donor ECU having a storage subsystem (24) breakdown. The slot-down process enables the use of a high physical address range by the non-donor processor provided with addressing capabilities sufficient only for addressing lower ranges.