Distributed Operating System

—A Distributed Operating System is the one that runs on multiple, autonomous CPUs which provides its users an illusion of an ordinary Centralized Operating System that runs on a Virtual Uniprocessor.

—Distributed Operating Systems provide resource transparency to the user processes.

  “If you can tell which computer you are using, you are not using a distributed operating system.” - Tanenbaum

—The Distributed Operating System is unique and resides on different machines.

— User processes can run on any of the CPUs as allocated by the Distributed Operating System.

— Data can be resident on any machine that is the part of the Distributed System.

— All multi-machine systems are not Distributed Systems.

“It is the software not the hardware that determines whether a system is distributed or not” - Tanenbaum

—Advantages:

-Price/Performance advantage (Availability of cheap and powerful Microprocessors).

-Resources Sharing

-Computation speed up – load sharing

-Reliability and Availability.

-Provides Transparency.

—Disadvantages:

1)Lack of security - Easy access also applies to secret data.

—An example of a distributed system: Amoeba

-An open source microkernel-based distributed operating system developed by Andrew S. Tanenbaum and others at the Vrije Universiteit.

-The aim of the Amoeba project is to build a timesharing system that makes an entire network of computers appear to the user as a single machine.

-Development seems to have stalled: the files in the latest version (5.3) were last modified on 12 February 2001.

-Amoeba runs on several platforms, including i386, i486, 68030, Sun 3/50 and Sun 3/60.




WRITER-->Shaidatul Hidayu bt Mohammad Sabri (F1051)