Transcript Network OS Concepts

CHAPTER
Network Operating
System Concepts
Chapter Objectives
• Provide an overview of network
operating systems and its functions
• Explain the concept of resources
• Outline the operating system
components
– Client OS, server OS, Domain etc.
• Introduce the concept of sharing data
and devices
Chapter Modules
• Network Operating System Overview
• Resources in a Network
• Operating System Components of a
Network
• Data and Device Sharing
MODULE
Network Operating System
Overview and Basic Functions
© N. Ganesan, All rights reserved.
Module Objectives
• Operating system definition
• Operating system: past and present
• Resources and users
• Managing resources
• Managing users
• Managing the network
Operating System Defined
Application Software
Operating Systems
Hardware
Network Operating System: Past
and Present
• Past
– Linked computers operating under
different operating systems
– Example: LAN Manager
• Present
– Operating systems by themselves
– Example: Windows NT Server
Network Operating Systems
• Controls and manages network
operations with respect to:
– Resources
– Users
Resources and Users
• Install
• Coordinate
• Control
• Manage
• Provide reliability and security
• Ensure continuity
Networking: Linking Users and
Resources
Security
Resource
Privilege
User
Effective Sharing
Managing Resources
• Install and ensure availability
• Enable secure access at different levels
– Read, write etc.
– Password protection
• Monitor performance
Managing Users
• Enroll users
• Provide secure privileges at different
levels
– Administrator
– Account manager
– Printer serve operator etc.
• Monitor usage
Managing the Network
• Backup features
• Fault tolerance
• Performance monitoring
• Trouble-shooting etc.
END OF MODULE
MODULE
Resources in a Network
© N. Ganesan, All rights reserved.
Module Objectives
• The concept of resources in a network
• Resources and objects
• Resource examples
• Resource identification
• Real world resource example
The Concept of Resources in
Networking
Subdirectory
Server
Printer
Disk
Storage
Modem
CD-ROM
Tower
Resources and Objects
• Any sharable object is a resource in the
network
– Logical and physical entities are not
distinguished from one another
• Terms used for the resource
– Share (Microsoft NT)
– Object (A developing general term)
Resource (Share) Examples
• Physical Examples
– Disk drives themselves, Printers etc.
• Logical Examples
– Subdirectories, Files etc.
Resource Identification
• By a given name
• By a drive letter, if desired and if
applicable
• By a name that conforms to the Uniform
Naming Convention (UNC)
Real Word Resource ID
Examples
Click to View
END OF MODULE
MODULE
Operating System Components
in a Network
© N. Ganesan, All rights reserved.
Module Objectives
• Operating system components in a network
• Server side operating system
– Multitasking, preemptive etc.
•
•
•
•
Client side operating system
A typical client-server OS implementation
Components of a named domain
A demonstration of a domain constituents
Major Components of the
Network Operating System
• Server-side operating system
• Client-side operating system
Server and Client Operating
Systems
Windows NT
Server
Client
Server
Windows 95/98
Server-side Operating System
• Generally known as the Network Operating
System
– Windows NT Server
• Coordinates and manages network access to
the resources
• Coordinates the functions of all computers
and devices in the network
• Provides security for access to network
resources
Multi-Tasking in NOS
• All NOSs are multitasking operating
systems
• Types of multitasking
– Preemptive
– Non Preemptive
Preemptive
• Operating system can take control of
the CPU overriding a task in execution
• A desired characteristic from a
networking point of view
• All recent NOSs are preemptive
operating systems
Non-preemptive NOSs
• Corporation from task is required
– For relinquishing possession of CPU to the
operating system
• Not desirable form a networking point
of view
• Found in old NOSs
Client
• Operating system for the client
– Windows 95/98
• Manages local client
• In a client-server environment
– Provides access to the services at the server
• In a peer-to-peer environment
– Manages local sharing of resources by
other peers as well
A Typical Client-Server OS
Implementation
NT Domain
Controller
File
Server
Client
Domain
Components of a Named Domain
• Named IDs
–
–
–
–
Domain
Server
Client
Shared devices
• Domain is a collection of servers, clients and
shared devices
• Multiple domains can be linked to form large
networks
A Real Example of a Domain
Click to View
END OF MODULE
MODULE
Data and Device Sharing
© N. Ganesan, All rights reserved.
Module Objectives
• Data sharing mechanism in a network
• Data sharing
– Physical and logical sharing
– The concept of soft resources
• Device sharing
– Physical and logical sharing
– The concept of hard resources
• Redirection of sharing request at the client
Data Sharing in a Network
Physical Presence
Logical Presence
F:
B:
Client
Shared
Director
C:
Server
Logical Data Sharing Notes
• A shared directory at the server is
shared at the client as a:
– local logical drive such as drive f:
– local logical directory/subdirectory with a
name
Logical Data Sharing Example
Click to View
Device Sharing in a Network
LPT1
Sever
Client
LPT2
Physical Local
Printer
Logical Shared
Printer
Shared
Printer
Logical Presence
Physical Presence
Logical Device Sharing Notes
• Devices are shared by installing the
device at the client as a network
shareable device
• Example:
– Local printer
• Attached to port Lpt1
– Network printer
• Attached to port Lpt2
Logical Device Sharing Example
Click to View
Redirection: The Essence of
Sharing at the Client
Local
Client
Redirector
Network
Server
Request for Reource
Notes on Redirector
• Redirector may be considered as a shell
in the client operating systems
• Purpose
– Filter local and network request for
resources
END OF MODULE
END OF CHAPTER