File, Database and I/O Systems Performance

有两种技术趋势强烈影响着设计， I/O系统的性能。 首先，处理器能力，尤其是对于 单（或少）芯片设计，增长非常迅速，导致： (a)I/O负载（几乎）相应增加，（B）分布 带有工作站（带/不带本地磁盘）、文件服务器和 计算节点，以及（c）具有巨大 与提供相同功能的单处理器相比， 总体业绩。 其次，磁盘存储密度不断增加 在磁盘性能没有任何可比的提高。 一些 设计和优化问题变得极其重要 由于这些趋势：（a）系统越来越容易受到 由于I/O速率的增加以及 提高I/O系统响应它们的能力。 （B） 具有共享I/O设备和/或数据库的多处理器系统 越来越容易受到引用、锁定 以及更新共享数据。 该项目继续研究与以下方面有关的若干专题： 文件、I/O和数据库系统性能。 这些措施包括： 分布式环境下磁盘缓存算法的研究与分析 和等级制度，同时考虑到一致性和 性能 (b)研究磁盘缓存的影响， 磁盘条带化和日志结构文件系统。 (c)分析和 开发用于共享分布式数据库的锁定算法 系统. (d)分层结构的设计、优化与实现 以及在非常大的海量存储系统中的分布式文件迁移 使用的是加州大学伯克利分校制造的光盘。 这项工作依赖于 主要依赖于实际系统测量和跟踪驱动仿真。

There are two technology trends strongly impacting the design and performance of I/O systems. First, processor power, especially for single (or few) chip designs, is increasing very rapidly, leading to: (a) (almost) corresponding increases in I/O load, (b) distributed systems with workstations (w/wo local disks), file servers and computation nodes, and (c) multiprocessors with enormous cost/performance advantages over uniprocessors providing the same aggregate performance. Second, disk storage densities are increasing rapidly without any comparable increase in disk performance. A number of design and optimization problems have become extremely important due to these trends: (a) Systems are becoming increasingly susceptible to I/O bottlenecks due to increasing I/O rates and the less quickly in creasing ability of the I/O system to respond to them. (b) Multiprocessor systems with shared I/O devices and/or databases are increasingly susceptible to I/O bottlenecks in referencing, locking and updating shared data. This project continues research on a number of topics relating to file, I/O and database system performance. These include: (a) Development and analysis of algorithms for disk caching in distributed and hierarchical systems, taking into account both consistency and performance. (b) Studies of the effect of disk caching in conjunction with disk striping and log structured file systems. (c) Analysis and development of locking algorithms for shared, distributed database systems. (d) Design, optimization and implementation of hierarchical and distributed file migration in a very large mass storage systems using optical disks to be built at UC Berkeley. The work relies heavily on actual system measurement and trace driven simulation.