A novel hint-based I/O mechanism for centralized file server of cluster

In the medium and small cluster systems, the centralized file server such as NFS is the main approach to provide the storage service with low cost and easy management. However, when multiple parallel applications access the shared storage at the same time, the I/O performance decreases much because of the interference of the I/O requests coming from the different clients. In this paper, a hint-based I/O mechanism is proposed and implemented in the United-FS. By analyzing the hint information of the I/O requests, the related requests are grouped, sorted and scheduled by our hint-based I/O scheduler. The experiments show that our hint-based I/O mechanism nearly doubles the read performance compared with NFS, and has better scalability.