Example apparatus and methods create and maintain a functional mirror of file system metadata for an active file system. The functional mirror may be implemented as a set of database tables that allow a journal functionality for information received from the active file system. Example apparatus and methods also restore the file system metadata from the functional mirror. Mirror creation and maintenance can operate in parallel. Mirror maintenance and metadata restore can also operate in parallel. The functional mirror may be created primarily using a systematic, system-wide, multi-threaded crawler approach whose results are updated using an event-driven approach that accounts for changes that may make obsolete information acquired during the crawler approach. The metadata may be restored using a systematic, system-wide, multi-threaded crawler approach acting together with an event-driven approach that restores certain files out of order as they are needed.