File system performance and transaction support

摘要: This thesis considers two related issues: the impact of disk layout on file system throughput and integration transection support in systems. Historic designs have optimized for reading, as read was I/O performance bottleneck. Since increasing main-memory cache sizes effectively reduce traffic (BAKER91), write has become bottleneck (OUST89). presents both simulation implementation analysis read-optimized write-optimized systems. An example a with writing is log-structured system, where writes are bundled written sequentially. Empirical evidence (ROSE90), (ROSE91), (ROSE92) indicates that provides superior equivalent to traditional systems. analyzes evaluates presented isolating some critical issues its design. Additionally, modified design addressing these evaluated. Log-structured systems also offer potential transaction processing into system. Because use logging techniques store files, incorporating mechanisms natural extension. design, implementation, user-level management embedded optimize system. This shows simple, can attain nearly 100% bandwidth when I/Os large or sequential. The improved LFS discussed only attainable garbage collection overhead small, all workloads examined, comparable On steady stream random issued, reduces by 35% 40%.