FARAD: A storage system for random real-time data

Many multimedia applications demand real-time and high throughput data retrieval from a storage subsystem. Very often, the access pattern of such retrieval has random nature. This is due to real-time playback of video clips that are physically separated on the disk platter (non-linear editing), or due to serving many independent clients simultaneously (VOD; video on demand).   In this paper, we describe a new real-time disk management algorithm that can significantly reduce the overhead incurred by random access. While existing algorithms treat the rotational delay as uncontrollable, our algorithm controls both seek and rotational delay by proper scheduling and data placement so as to reduce overhead in a random data access environment.