Marshall K. McKusick

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A reimplementation of the UNIX file system is described. The reimplementation provides substantially higher throughput rates by using more flexible allocation policies that allow better locality of reference and can be adapted to a wide range of peripheral and processor characteristics. The new file system clusters data that is sequentially accessed and(More)
Large complex programs are composed of many small routines that implement abstractions for the routines that call them. To be useful, an execution profiler must attribute execution time in a way that is significant for the logical structure of a program as well as for its textual decomposition. This data must then be displayed to the user in a convenient(More)
Research results [ROSE91] demonstrate that a log-structured file system (LFS) offers the potential for dramatically improved write performance, faster recovery time, and faster file creation and deletion than traditional UNIX file systems. This paper presents a redesign and implementation of the Sprite [ROSE91] log-structured file system that is more robust(More)
Traditionally, filesystem consistency has been maintained across system failures either by using synchronous writes to sequence dependent metadata updates or by using write-ahead logging to atomically group them. Soft updates, an alternative to these approaches, is an implementation mechanism that tracks and enforces metadata update dependencies to ensure(More)
1 Abstract The UNIX Fast File System (FFS) is probably the most widely-used file system for performance comparisons. However, such comparisons frequently overlook many of the performance enhancements that have been added over the past decade. In this paper, we explore the two most commonly used approaches for improving the performance of meta-data(More)
Metadata updates, such as file creation and block allocation, have consistently been identified as a source of performance, integrity, security, and availability problems for file systems. <bold>Soft updates</bold> is an implementation technique for low-cost sequencing of fine-grained updates to write-back cache blocks. Using soft updates to track and(More)