LSF: a new buffer replacement scheme for flash memory-based portable media players

A portable media player is a consumer electronics device that is capable of storing and playing digital media such as audio, image, video, and etc. NAND flash memory has been widely deployed as a storage medium for these portable media players because of its small size, light weight and low power consumption. However, due to distinct characteristics of NAND flash memory such as no in-place update, asymmetric operation unit and speed, conventional disk-based buffer replacement scheme may not yield good performance on flash memory-based storage systems. In this work, we propose a novel buffer replacement scheme considering the features of metadata as well as multimedia data for portable media players. Our proposed scheme classifies the pages into a long sequential reference set and a short sequential reference set by checking the sequential continuity of pages in the buffer. And then, it mainly evicts long sequential reference sets first from the buffer and keeps short sequential reference sets in the buffer as long as possible to improve the hit ratio. By this strategy, we can efficiently reduce the number of write and erase operations to the flash memory when storing and playing digital media. Through various experiments, we show that our proposed scheme yields better performance than its related work¹.