A method for dynamically optimizing file systems based on user access patterns or other parameters. According to an embodiment of the present invention, a list of files forming a cluster is first created based on various preset criteria by an application, the list is transmitted to a file system program, and then the file system optimizes allocation of files in a storage medium based on the list. Embodiments of the present invention can be used to rearrange files stored in a storage medium so that files which tend to be used together are stored closer to each other. This can substantially reduce a typical application launch time.