A system and method for utilizing slack space as another file system. The system identifies available slack space caused by storing data on a drive. The slack space is then made available as part of a separate file system. The separate file system allows for dynamic cluster sizes as the cluster size depends on the slack space of each individual file. The available space for the file system also dynamically changes based on the change in slack space caused by new data files being stored on the drive, edits to data files on the drive, or deletion of data files.