Trace-based analysis has always been used to guide and motivate more effective hardware and software design. Existing traces available, however, are unsuitable for studying object-based storage system, a very active area of current storage research, because they are collected from the traditional file systems and don?t contain information about object. Thus, a kind of distributed object tracing system is presented in this paper which built on the object-based Lustre file system.

The tracing system regards object as capturing unit which we also call it object-trace. Objects information is synchronously captured from three software subsystems of Lustre cluster file system, and eventually integrated into one entire trace for every request of each user. To improve I/O performance and efficiency, we employ a ring of buffers to store trace data which finally is written out to a trace file by an output driver. In particular, we use some database tables to save the final incorporated traces for convenient post-analysis. A prototype of object tracing system is designed and implemented on Linux.