Functions of an Operating System
Operating Systems is a computer program that controls the operation of the hardware of a computer and the execution of programs. The primary functions of an operating system include:
1) Managing and controlling the hardware of the computer, e.g., drivers
2) Interfacing between hardware and software, i.e. how programs and applications use hardware – keyboard, mouse, monitor.
3) Managing memory, i.e., multitasking, multiprocessing and threads
4) Managing and executing applications
5) Diagnosing problems with software and hardware
6) Managing Storage Devices and Files, e.g., NTFS and Netware file system
7) Providing a User Interface
Additional Functions of a Network Operating System
Where multiple hosts share the workload and resources, but each host executes its own programs
1) Connecting to the Network, e.g., network interface card drivers, communication protocols, and client services.
2) Enabling remote users to access and share resources, and user interfaces to use various share services, e.g., utilities, web access, SMTP.
3) Provide additional security to access shared resources, i.e., authorization (logon) and authorization (resources) services.
4) Provide applications for network use, e.g., Web, SMTP, and DHCP servers.
5) Provide network diagnostics utilities.
Types of Network Operating Systems
Peer-to-Peer or Workgroup Model
Any computer can be a server or a client, or both. Examples of these NOS include Microsoft Networking and Windows 2k Member servers The security system is decentralized, and is stored in the local registry. Practical for networks up 5 to 10 computers with limited sharing and low security requirements. Every server maintains its own security system. this means that you must have a password on each server.
Peer-to-Peer or Workgroups
No centralized control over resources
Resources are distributed across all computers
No centralized account management
Little administrative overhead
No centralized administration
Simple to design
No centralized security system
Easy to implement
Inefficient for more than 20 computers
Convienent for small groups in close proximity
Security must be configured manually
Less expensive or free software, does not require a centralized server
Increased training to educate users to use their computer as both a client and a server.
Domain (Client/Server) Model
The designation of one computer to centralize the administration of shared resources and security. It is generally recommended that a computer would be only used as either as a client or a server, but not both. For example, share files will be stored on the server. Windows NT/2K domain controllers, Active directory and Netware are examples of the client Server model.
Client/Server or Domain Model
Centralized resource sharing
Significant administrative effort and overhead
Centralized resource control
Complicated designs; requires advanced planning
Centralized account management
Requires one or more powerful, expensive servers (especially for Win NT/2K)
Centralized security management
Absolute security is hard to achieve when the security system is so powerful and still managed by people
Efficient for virtually unlimited number of workstations
Expensive for domain controllers and NDS replica servers, and access lags increase network traffic
Users need only be trained for clients
Some increased level of knowledge is required by network administrators
Can be used to connect to remote networks or clients
Larger scope requires more documentation and training
May be able to connect to a variety of client operating systems and versions.
Licensing fees may be costly. Perhaps that is why Linux is growing in popularity
May lower the Total Cost of Ownership (TCO), e.g., Distributing applications and upgrades, remote desktop control, and inventory features, etc. (Z.E.N.)
There are two types of Domain or Client Server models:
Single Domain or Single Server Model
In previous years
Directory Services or Multiple Server Model
Win NT Server
Win 2k Server
Single Processors Performance
All Apps Run at Ring 3
Some apps and functions move to Ring 0
A, Apps are NLMs
AA, specify apps to run at ring 3
AA, Ring 3 gave stability
E, E-commerce – Datacenter
AA, Unix on some type of mainframe instead
Clustering- Sharing execution of tasks between servers
Applications, Web servering, Inventory
Very limited, own Server language
Introduced Internet appls
Expected to be better
AA, used to the api as other microsoft products
E, Internat applications good, other stink
Interfacing with Windows Desktops
security can be stored in a database or part of the file system}
Ease of Installation
AA, PNP was just i
AA, No PnP
AA, 1.2 PNP
Ease of Network Management
Multiple Server Support
NDS, X.500. hierarchical 1994 multiserver system
Is a database security system that uses a file system
NDS, multiple trees
Domain, one security, easier than bindery but not even close to NDS
Active Directory, LDAP Mulit server/domain, a database that integrates the file system security
Schema extension, the ability to modify and customize the security system
SPX/IPX was required with slight support to Tcp/Ip
Tcp/ip by itself
Network Protocol support
Difficult, but powerfule
But who has experience
DOS Fat 16
Intsalls a file system
Right click on the disk, or Disk management
Partitions the hard drive
List files stored in a folder/subdirectory
More info, e.g., Owner of the file and the date/time the file was last accessed Netware file system
Windows Excplore, can view extended Netware Info if the correct client was installed
Copy select files to a different location
Copy file1 H:
Between the local hard drive and the server it makes no differnce.
Copying files between folders on the same server or between server there is a major difference
Copy and paste, Netware copy
Change or View Date/time
operating system date/time
server date and time
several file servers
SYSTIME or most Windows Os are defaulted to synchronize during login
New Features of Netware 6.X
1) Novel’s OneNet – Strategy to developa product line that helps make the various Internet’s many diverse network operating system operate as one. That is to provide various Internet applications that work across different network environments. For example, the following Netware products can run on Windows NT, Windows 2000 and Linux servers, beside its native platform Netware.
eDirectory is a global security database that provides a list of user names and shared network resources (printers, files, folders, etc.) that can used to access multiple servers using multiple network operating systems. Running on multiple platforms allows networks consisting of diverse clients and servers appear as one. Formally, eDirectory was called NDS (Novell Directory Services) and was managed by a utility program call NWAdmin32. While this Netware Management Utility is still available is does not support all of the new features of Netware 6.x, and it must be executed on Windows, 9x, 2000 computer with a Netware Client installed. In a Netware 6.x environment the tree structure ConsoleOne is the preferred Management Program and can be executed on multiple operating systems since it was written in Java. IManager is a web-based product that be used form any Web Browser. At this time it is not as powerful as Nwadmin or ConsoleOne.
Z.E.N.Works is an application management tool to help network administrators deliver applications to user workstations without having to intsll the application software at each workstation.
iFolder – is a seriver that users can access their data across the Internet using any Web browser, independent of the client’s local operating system and various remote locations not connected to the local area network. Advnatages include: a) a simple secure way to access, organize and manage files from any computer, b) Automatic synchronization of data across multiple workstations, c) file encryption on the server, and d) the ability to work offline and then have the file automatically synchronized (for example for a laptop). The use of ifolder requires the installation of an Ifolder server and an iFolder client
Novell NetStorage – provides remote secure access to files through a Web Browser, instead of an iFolder client. Though an iFolder client is not required, the server must be prepared on the server through a NetStorage installation process.
iPrint and the Internet Printing Protocol – provides the ability to print to Netware printers without requiring installation of the printer driver and NDPS printer agent. In Netware 5.x it was required to install a NDPS to send output to a NDPS printer. By installing the iPrint Client on a client through a web-based installation program, a client workstation can direct output to any NDPS printer through the Internet Printing Protocol.