Design considerations for the symphony integrated multimedia file system

摘要

A multimedia file system supports diverse application classes that access data with heterogeneous characteristics. In this paper, we describe our experiences in the design and implementation of the Symphony multimedia file system. We first discuss various methodologies for designing multimedia file systems and examine their trade-offs. We examine the design requirements for such file systems and argue that to efficiently manage the heterogeneity in application requirements and data characteristics, a multimedia file system should enable the coexistence of multiple data-type-specific and application-specific techniques. We describe the architecture and novel features of Symphony and then demonstrate their efficacy through an experimental evaluation. Our results show that Symphony yields a factor of 1.9 improvement in text response time over conventional disk scheduling algorithms while continuing to meet the real-time requirements of video clients. Finally, we reflect upon the lessons learned from the Symphony project.