A system for managing file systems includes memory. The system also includes a manager. The memory is used for storing in-memory data structures. The manager obtains file system references for a file system from a file system manager. The file system manager utilizes storage to provide the file system references. The manager stores the file system references in an in-memory data structure in the memory. To service file system reference requests, the manager utilizes uses the in-memory data structure to service at least one of the file system reference requests.