Improving file system performance and reliability of car digital video recorders

Car digital video recorders (DVRs) store realtime audio/video data at flash memory storage device. Car DVR should handle a large amount of high quality multimedia data with high reliability. However, current file systems are vulnerable to sudden-power-offs and flash memory errors. This paper proposes flash-aware cluster allocation techniques and a flash-aware journaling technique. The flash-aware cluster allocation techniques can reduce the probability of file system corruptions and file fragmentations. The flash-aware journaling technique can ensure the file system consistency without significant overheads. Experiments on a simulator and a real system showed that the proposed techniques can prevent file fragmentations and file system corruptions, and they can improve the write performance and lifetime of SD card significantly.