Performance Analysis of the COSMOS File System

COSMOS file system provides single system image (SSI) and strict Unix semantics. It guarantees user level binary compatibility with general Unix file systems, and is designed to be a scalable system. No bottleneck of centralized service is introduced. All data, including metadata and directory files, are distributed into the whole system to provide high performance and scalability. Our tests show satisfactory bandwidth and overall performance of COSMOS, and the system scales well. We discuss the key factors affecting the system performance and scalability. Based on implementation experience and test data, we discuss the bottlenecks of the existing system and propose methods for future improvement.