A method for execution by a storage unit in a dispersed storage network (DSN) includes selecting a storage zone of a memory device of the storage unit based on zone allocation parameters, and designating the selected storage zone as open for writes. A data slice is received via a network for storage. The data slice is written sequentially at a memory location of the one of storage zone based on determining that the storage zone is designated as open for writes. A pointer corresponding to the data slice that indicates the storage zone and the memory location is generated. A read request is received via the network from a requesting entity that indicates the data slice. The data slice is retrieved from the memory device based on the pointer, and is transmitted to the requesting entity.