A data storage system can arrange semiconductor memory into a plurality of die sets that each store a top-level map with each top-level map logging information about user-generated data stored in a die set in which the top-level map is stored. A journal can be stored in at least one die set of the plurality of die sets with each journal logging a change to user-generated data stored in the die set of the plurality of die sets in which the journal and top-level map are each located.