One of the most difficult problems in distributed systems is load-balancing. Even if we take care of load-balancing, heavily-loaded nodes often occur while there are still lightly-loaded nodes that have idle memory and idle CPU power. Our idea is to exploit this idle memory and idle CPU power to improve the storage performance of heavily-loaded nodes. Idle memory can be used for caching file data and idle CPU power can be used for extracting file access patterns from file access logs. File access patterns are valuable sources for optimizing a cache strategy. Our project goal is to improve the overall performance of distributed systems by improving storage access performance. This paper gives an overview of this project idea and reports the current status of the project. In addition, we show benchmark results from our prototype cache extension system, which is implemented in Linux Kernel 2.6. The DBT-3 (TPC-H) benchmark results show that our system can increase computer speed by a factor of 6.68.