DescriptionModern supercomputer applications are demanding powerful storage resources in addition to fast computing resources. However, these storage resources, especially parallel shared filesystems, have become the Achilles' heel of many powerful supercomputers. A single user's IO-intensive work can result in global filesystem performance degradation and even unresponsiveness. In this project, we developed an innovative IO workload managing tool that controls the IO workload from user applications' side. This tool is capable of automatically detecting and throttling intensive IO workload caused by supercomputer users to protect parallel shared filesystems.