As the speed gap between memory and disk is so large today, caching and prefetch are critical to enterprise-class storage applications, which demands high-performance. In this paper, we present our study on performance of a mid-range storage server produced by the Quanta Computer Incorporation. We first analyzed the existing caching mechanism in the server and then developed a fast caching methodology to reduce the cache access latency and processing overhead of the storage controller. In addition, we proposed a new adaptive prefetch scheme reduces the average disk access time seen by the host. Via trace-driven simulation, we evaluated the performance of our new caching and adaptive prefetch schemes. Our results showed the performance improvement for the TPC-C on-line transaction benchmark.