A file storage system may be implemented by coordinating non-exhaustible and exhaustible storage devices. The exhaustible storage devices may be lower grade flash based storage devices. The non-exhaustible storage devices may be storage devices based on magnetic recording mechanisms or higher grade flash storage. The file storage system may store received content items on the exhaustible storage devices. The file storage system may additionally store metadata for the content items and/or the file storage system on the non-exhaustible storage devices. During operation, the file storage system may globally optimize the content items on the exhaustible storage devices such that more heavily accessed items are moved to exhaustible storage devices that have experienced relatively few data operations. The file storage system can move less frequently accessed content items to exhaustible storage devices that have experienced a relatively large number of data operations. As such, the operation lifetime of the exhaustible storage devices as a whole can be prolonged.