Abstract: A storage system may have multiple storage devices on which files are stored. The system may determine various performance characteristics for each storage device and select a storage device on which a particular file having a set of characteristics may be stored. The storage system may consolidate disparate storage devices, such as hard disks, solid state memory devices, and other devices into a single virtual storage device accessible to an operating system. A monitoring system may track file usage information and storage device performance and usage, and an optimizer may transfer files to different storage devices to periodically optimize the file placement based on such usage information.