Stacked mapped storage system

摘要: A stacked map storage system has a base mapping of logical data to physical locations in the system. Level maps are created either as positive or negative lower level map. enables an alternate view while keeping next lowest same. allows changes but stores references itself so becomes backup. Negative freeze themselves and read-only. can be used by applications under test make changes, not allowing made through In preferred embodiment, any number levels, shared hosts, deleted merged. Deletion removes though it never existed. merge overlays upper onto thus match other's state. Both merger deletion manipulate only information do change move stored data.