This document discusses distributed operating systems. It begins by defining a distributed system as multiple connected CPUs that appear as a single system to users. A distributed operating system provides the essential services of a traditional operating system but runs across multiple independent CPUs. It aims to be transparent to users. Examples given of distributed operating systems include Amoeba, Solaris, and MOSIX. The document outlines the features, functions, and goals of distributed operating systems, such as resource sharing, accessibility, concurrency, scalability, and fault tolerance.

1. Distributed Operating
System
Introduction
By
Vijay Kumar Verma (VJY)
Roll No-1326910
04-March-2014

2. Objectives
What Why When
Features & Goal
Functionality
Examples
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3. What is Distributed System?
 A distributed system:
 Multiple connected CPUs working
together
 A collection of independent computers
that appears to its users as a single
coherent system. ~Tanenbaum
 Distributed program running on it.
 Distributed programming is used to
write Distributed program.
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4. Contd…
What is Distributed System?
 Distributed computing is field of
computer science where we learn about
 It is easy to expand and scale.
 Computer networks where individual
computers were physically distributed
within some geographical area.
 Main goal solve large computational
problem.
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5. Contd…
What is Distributed System?
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6. Why need, When use
 Much better performance ratio
 Resource sharing
 Enhanced performance -tasks can be
executed concurrently; load distribution
to reduce response time
 Higher reliability - data replication
 Easier modular expansion -- hardware and
software resources can be easily added
without replacing existing resources
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7. Differentiation with Parallel
Systems
 No need of shared memory
 Communication via message passing
 No need of homogeneity
 DS consists of different types of
hardware and software.
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8. Challenges
 Heterogeneity
 Distribution transparency
 Fault tolerance
 Scalability
 Concurrency
 Openness
 Security
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9. Models
 Tanenbaum and Renesse classified
distributed systems into three
broad categories
1. Minicomputer Model
2. Workstation Model
3. Processor Pool Model
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10. Types
 Distributed Computing System
 Distributed Information Systms
 Distributed Pervasive systems
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11. Example
 World Wide Web (WWW) is the biggest
example of distributed system.
 Others are
 The Internet.
 An Intranet which is a portion of the
internet managed by an organization.
 Multimedia production house
 Space research
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12. What is Operating System?
 An operating system (OS) is:
 a software layer to abstract away and
manage details of hardware resources
 a set of utilities to simplify application
development.
Applications
OS
Hardware
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13. Evolution of OS
 OS generation can be classified in four
type. Following is the types with their
goals:1.
2.
3.
4.
BY: VJY
Centralized OS ~ Resource Management
Network OS ~ Resource Sharing
Distributed OS ~ Transparency
Cooperative OS ~automaticity
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14. Distributed Operating System?
 A distributed operating system is one
that looks to its users like an ordinary
centralized operating system but runs
on multiple, independent central
processing units (CPUs).
 The key concept here is transparency.
 A distributed OS provides the essential
services and functionality required of
an OS.
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15. Now
What Why When
Features & Goal
Functionality
Examples
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16. Features & Goal
 Resource sharing
 Accessibility
 Openness
 Concurrency
 Scalability
 Fault Tolerance
 Transparency
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17. Now
What Why When
Features & Goal
Functionality
Examples
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18. Functions









Process management
Inter-process communication
Process management
Resource management
Reliability
Availability
Performance
Synchronization
Flexibility
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19. NOS vs DOS
 NOS are considered here to be those which
provide support for networking and
remote resource access, often by a
separate layer of software on top of a
conventional OS.
 DOS strive for a high degree of
transparency and often support data and
process migration. Users normally do not
distinguish local resources from remote
resources.
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20. Now
What Why When
Features & Goal
Functionality
Examples
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21. Examples
 AMOEBA OS ~Andrew S. Tanenbaum
 Solaris OS ~SUN Microsystem
 MOSIX ~Hebrew University of Jerusalem
(Professor Amnon)
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22. Have Any Question?
Just Ask!
Post Query On
facebook.com/groups/sviet.mca
Email@
vjy.softworx@gmail.com

23. Thank You!
Vijay Kumar Verma