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 provides two block sizes to allow fast access to large files while not wasting large amounts of space for small files. File access rates of up to ten times faster than the traditional UNIX file system are experienced. Long needed enhancements to the programmers’ interface are discussed. These include a mechanism to place advisory locks on files, extensions of the name space across file systems, the ability to use long file names, and provisions for administrative control of resource usage.

Areimplementation 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 provides two block sizes to allow fast access to large files while not wasting large amounts of space for small files. File access rates of up to ten times faster than the traditional UNIX file system are experienced. Long needed enhancements to the programmers’ interface are discussed. These include a mechanism to place advisory locks on files, extensions of the name space across file systems, the ability to use long file names, and provisions for administrative control of resource usage.

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 provides two block sizes to allow fast access to large files while not wasting large amounts of space for small files. File access rates of up to ten times faster than the traditional UNIX file system are experienced. Long needed enhancements to the programmers ' interface are discussed. These include a mechanism to place advisory locks on files, extensions of the name space across file systems, the ability to use long file names, and provisions for administrative control of resource usage. Revised February 18, 1984 CR Categories and Subject Descriptors: D.4.3 [Operating Systems]: File Systems Management - file organization, directory s...

Smalltalk is an object-oriented programming language and highly interactive uniformly object-structured programming environment, originally developed for the Xerox family of personal workstations. The Smalltalk programming environment supports a single user on a single processor in a single object address space. This thesis describes the design and implementation of Distributed Smalltalk. Distributed Smalltalk extends the Smalltalk system to support the interaction of many users on many machines. It provides communication and interaction among geographically remote Smalltalk users, direct access to remote objects, the ability to construct distributed applications in the Smalltalk environment, and a degree of object sharing among users. Applications of Distributed Smalltalk include mail systems, remote computation servers, remote file servers, and collaborative software development. The distributed aspects of the system are largely user transparent and preserve the reactive quality of Smalltalk objects. A system is reactive to the degree that objects in the system can be easily presented for inspection or modification. Smalltalk is highly reactive in that all objects in the system can be so presented. Inheritance is a fundamental property of Smalltalk that allows objects to acquire behavior from other objects. In designing Distributed Smalltalk, we found that the interaction of inheritance and reactiveness was a major source of difficulty and that this interaction had significant impact on the design of a distributed system. Neither inheritance or reactiveness scaled well fro...

Areimplementation 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 provides two block sizes to allow fast access to large files while not wasting large amounts of space for small files. File access rates of up to ten times faster than the traditional UNIX file system are experienced. Long needed enhancements to the programmers’ interface are discussed. These include a mechanism to place advisory locks on files, extensions of the name space across file systems, the ability to use long file names, and provisions for administrative control of resource usage.