Network Operating Systems

1. Network Operating Systems ISQA424 Instructor: Rob Knauerhase Portland State University

2. Chapter 1: Networking with Microsoft Windows NT Server

3. Learning Objectives • Explain workgroup networking • Explain domain networking and the advantages of file server operating systems • Present a history of how Windows NT Server evolved • Describe the capabilities of Microsoft NT Server continued

4. Learning Objectives • Compare different file systems used by Microsoft NT Server • Discuss how Microsoft NT Server is integrated with Internet and intranet applications

5. Workgroup Networking • Microsoft Windows NT Server is a network operating system -- software that enables computers on a network to communicate and share resources and files • Peer-to-peer network: A network where computers communicate with each other on an equal basis without going through an intermediary

6. Workgroup Networking • Workstation • A computer that has its own CPU • May be used as a standalone computer for a variety of software applications • Workgroup: As used in Microsoft networks, a number of computers (users) who share drive and printer resources in an independent peer-to-peer relationship

7. A Simple Peer-to-Peer Workgroup Workstation Workstation Workstation Workstation Workstation

8. Workgroup Networking • Effective for small networks or offices • Less effective when resource management is totally decentralized • Offers only moderate network security • No centralized storage or account management • No point of centralized administrative control • Not optimized for heavy multiple access to one computer; potential for slow response

9. Networking in a Domain • Domain: A grouping of network users and file servers to make common administrative and security management tasks more efficient • File server: A computer that provides files and other services to workstations.

10. A File Server on a Network File server with NT Server operating system Workstation Workstation Cabling Workstation Laptop computer

11. Advantages of the Domain Model • All members can share computer files • Printers and other resources can be shared • Access to resources can be centrally controlled and administered • Members can share software applications (consistency) continued

12. Advantages of the Domain Model • All computers can be backed up from one location (easily) • Sharing of resources can reflect work groupings within the domain • Network administrator can save time when installing software upgrades • Detailed monitoring and analysis can be done from a central location

13. A History of Microsoft Windows NT • Work began in 1988 when Microsoft had two operating systems • MS-DOS (& early Windows versions) • OS/2 (co-developed with IBM) • Design focused on providing broader capabilities in areas key to business and network users • e.g., needed a “real” operating system • competitive pressure from Mac, Unix

14. Original Windows NT Development Goals continued

15. Original Windows NT Development Goals

16. Sharing resources Managing resources Security Scalability and compatibility Reliability Distributability Client/server applications Electronic mail Fault tolerance Microsoft Windows NT Server Capabilities

17. Sharing Resources • Files needed by several people can be stored at one location • Mapped drive: A disk drive that is shared on the network by a file server or workstation. Also known as a drive share. • Data are consistent across machines • Many kinds of printers can be shared on a network • Software can be loaded or run on workstations across network (site license)

18. Workstations Accessing a Shared NT Server Hard Drive Workstation Windows NT Server Shared drive Network Workstation

19. Workstations Sharing One Printer Workstation Workstation Workstation Workstation File server Workstation Shared printer Workstation Hub

20. Managing Resources • Centralizing management of resources allows a network administrator to simplify network management tasks • Network resources • File servers • Workstations • Shared printers • Shared folders

21. Security • Windows NT Server has a C2 top secret security rating from the US government • File and folder protection • Account passwords • File, folder, and account auditing • File server access protection on a network • File server management controls • This is a minimum of security; by no means is it perfect.

22. Scalability and Compatibility • Scalability • Works on single-processor and multiprocessor computers • Handles small or large databases • Compatibility • Communicates with IBM, Novell, UNIX, Banyan, DEC, and other systems • Works with all (most?) PC hardware, much existing Windows software.

23. Reliability • The NT Server operating system kernel runs in privileged mode • Protects operating system from problems created by malfunctioning program • Gives operating system an extra level of security from intruders • Prevents system crashes because of out-of-control applications

24. Reliability • NT Server takes full advantage of multitasking and multithreading capabilities of modern Pentium computers • Multitasking: Ability to run two or more programs at the same time • Multithreading: Ability to run several program processes or parts (threads) at the same time

25. Distributability • Distributability: The process of dividing complex application program tasks among two or more computers • Windows NT Server handles it through the Distributed Component Object Model (DCOM)

26. Client/Server Applications • Began appearing in late 1980s • Provide more information to users than traditional mainframe (unable to meet reporting and data query needs) or file-server-based application systems (unable to handle large databases) • Focus on quickly bringing data to customers

27. Technological Tools of Client/Server Applications • Relational databases • Graphical user interfaces (GUIs) • Powerful reporting tools • More powerful PC workstations • Networks

28. Relational Databases • Store large amounts of data on a server • Provide fast access to data for updating, querying, or reporting • Store data, voice, and video • Provide open access paths to a variety or reporting and development tools

29. Three Tiers of Client/Server Systems • PC client workstation • Contains GUI presentation logic • Application server • Stores client/server applications and reports used by client • Database server • Provides data-related services, including security

30. Client/Server Application System Application server (business process services) Database server (data services) Client workstation (GUI presentation services

31. Electronic Mail • Critical network application • even grandmothers have E-mail these days... • Fast and convenient • companies see strong benefits from E-mail interaction • among employees • between employees and customers • Enables use of distribution lists • much like isqa424@sba.pdx.edu

32. Fault Tolerance Options • Recovery from hard disk failures • Recovery from lost data in a file • Recovery from system configuration errors • Protection from power outages • Advanced warning about system and hardware problems • Recovery from network connectivity failures

33. Server File Systems • File allocation table (FAT) file system • NT file system (NTFS) • NT also allows conversion of the High Performance File System (HPFS) to NTFS • eases transition from OS/2

34. FAT File System • Based on the use of a file allocation table, a flat table that records the blocks used to store the data contained in each file on a disk • blocks - units of disk storage • Used by several operating systems (MS-DOS, Windows 95, Windows NT) • Does not support advanced security and auditing

35. Advantages of FAT • Simple system, supported by many small computer operating systems • Low operating system overhead • Supports partitions up to 4 GB

36. Disadvantages of FAT • Can become corrupted over time as files are spread among disjointed allocation units, and pointers to each unit are lost • Does not offer many file or directory security or auditing options • Does not support long filenames (11 character limit, “8 dot 3” convention)

37. NTFS • Native Windows NT file system • Has a detailed directory structure • Supports C2 security specifications • Supports large disks, long filenames, and file compression • Keeps a log of file system activity • Supports Portable Operating System Interface (POSIX)

38. HPFS • Used by the OS/2 operating system • Not supported by Windows NT 4.0

39. Choosing a File System continued

40. Choosing a File System

41. Internet Integration and Electronic Commerce • Internet • Global network of diverse WWW and information servers offering voice, video, and text data to millions of users • Major source of commerce • Intranet • Private network within an organization • Restricted from public access

42. Internet Information Server (IIS) for NT Server • Gives organizations ability to take advantage of intranet and Internet software • Index Server: Built-in service which automatically indexes information created for intranet access within a company

43. Chapter Summary • Windows NT Server is an operating system meant for networking. • Provides more options for network productivity and growth • Offers many resource options for shared folders, printers, and other resources • Provides network management facilities through domains and groups • Has built-in protection from crashes continued

44. Chapter Summary • NT Server enables scalability and distributability. • Gives options to scale up to larger and more powerful hardware • DCOM compatibility offers solid foundation for distributed application services such as client/server applications continued

45. Chapter Summary • NT Server supports FAT and NTFS. • Installation depends on file sizes, volume size, security needs, and purpose of server and number of users • NT Server offers access to and integration of Internet and intranet services through Microsoft’s Web server software, IIS, and built-in Index Server service.