This thesis considers two related issues: the impact of disk layout on file system throughput and the integration of transaction support in file systems. Historic file system designs have optimized for reading, as read throughput was the I/O performance bottleneck. Since increasing main-memory cache sizes effectively reduce disk read traffic [BAKER91], disk write performance has become the I/O performance bottleneck [OUST89]. This thesis presents both simulation and implementation analysis of the performance of read-optimized and write-optimized file systems. An example of a file system with a disk layout optimized for writing is a log-structured file system, where writes are bundled and written sequentially. Empirical evidence in [ROSE90], [ROSE91], and [ROSE92] indicates that a log-structured file sys...