Flash devices has become an important storage medium in enterprise hybrid storage systems. Buffer manager is a central component of database systems. However, traditional disk-oriented buffer replacement strategies are suboptimal on flash memory due to the read-write asymmetry. In this paper, we propose a cost-aware buffer management policy CARF for flash memory. We devise a novel cost model with low computational overhead to make more accurate decisions about page eviction. Moreover, this cost model can distinguish read and write operations as well as have better scan resistance. Experiments on synthetic and benchmark traces show that CARF achieves up to
improvement than state-of-art flash-aware buffer management strategies.