The "hardware" of the computer is made up of four basic parts:  

Ø        Central Processing Unit (CPU) 

Ø        Memory  

Ø        Secondary storage (disks)  

Ø        Input/output (I/O) devices (terminals, printers, tapes)

 These can do nothing without some software or instructions that can be executed by the CPU and tell it how to access other devices and process information received from them. The "operating system" is the basic software that is always accessible to the CPU (either always in memory or in a known location that can be loaded into memory as needed) that tells it how to access and control the resources of the computer.

Functions of the operating system:

Ø      Manage the physical resources of the computer - know how to get data from the disk or talk to a terminal.

Ø      Arbitrate between processes and users - decide which process (program) gets the CPU or the use of peripherals, for how long, in what order.

Ø       Create an environment to support user programs: provide a set of basic utilities so that programs can run without needing to know the detailed characteristics of the particular hardware. For example, the operating system provides routines to open a file and read it without having to know the specific geometry of the disk. back

Windows NT Server currently occupies the top spot in the hierarchy of Microsoft operating system products. It can be used to handle a wide range of tasks, from workgroups to enterprise networks. The server can handle file and printer services as well as Microsoft BackOffice products like Microsoft SQL Server, Microsoft Exchange Server, and Microsoft SNA Server. Microsoft® Windows NT® Server 4.0 is now a better choice than ever. With the new features introduced with the Windows NT 4.0 Option Pack, Windows NT Server is the most complete platform available for building and hosting Web-based applications, and the easiest server operating system available. You will be up and running less than an hour after you take it out of the box. It's so flexible and compatible you will realize significantly reduced hardware and software costs. You will experience far less downtime thanks to its reliability and easy management. Apart from being the host operating system for a number of computer applications, Windows NT Server offers the following advantages:

Ø        The operating system is optimized to provide high file, print, and application performance. This is achieved by its support for symmetric multiprocessing. The retail version of Windows NT supports up to four processors, while the OEM version supports up to 32 processors. 

Ø        It supports RAID technology for providing fault tolerance. 

Ø        It supports Remote Access Service (RAS) – Windows NT Server supports 256 inbound RAS connections as compared to one inbound connection for Windows NT Workstation. 

Ø        It provides a high level of domain security through its Windows NT Directory Service (NTDS) – a directory database that is replicated across a number of backup servers, which contain user-level rights and access permissions. 

Ø        It supports Hyper Text Transfer Protocol (HTTP) and File Transfer Protocol (FTP) services through its Internet Information Service. 

Ø        It supports Domain Name System (DNS), Dynamic Host Configuration Protocol (DHCP), Windows Internet Name Service (WINS), multi-protocol routing, and file and print sharing services for Macintosh clients. 

Windows NT Server has a number of advantages over the other operating systems in the Microsoft family, but these advantages result in a higher minimum configuration requirement. These requirements are listed below: 

Ø        486DX (33Mhz) computer or above.

Ø        16 MB of RAM. 

Ø        At least 130 MB of free disk space.

Roll Over Independent software vendors (ISVs) are rallying behind NT as a rival application server platform for database management, transaction processing, business processes and Internet/intranet services, especially for small-to-midsize markets, for a number of reasons:

Ø        Windows NT supports the Intel x86 architecture, creating a generous range of hardware options. Microsoft also supports Digital Equipment Corp.'s powerful Alpha architecture with NT. 

Ø        Windows NT not only supports multitasking and protected memory; it also offers an industry-standard API for developing applications. Unlike writing Unix applications, an ISV isn't forced to decide which vendor's API to support for NT applications. The NT API is identical in all copies of Windows NT--and porting to a different architecture (such as Digital's Alpha) involves nothing more than recompiling the code, not rewriting the application.  

Ø        Windows NT Server provides native file and prints services for Windows workstations out of the box. Microsoft's goal is to provide a single platform solution for all servers needs. However, even though Microsoft has made a considerable push toward TCP/IP networking, these file and print services are still based on antiquated Server Message Block (SMB) and NetBIOS.  

Ø        Windows NT's standard graphical user interface and slew of GUI-based management applications simplify server administration, theoretically reducing support costs.  

Ø        Microsoft's stature as a major industry player virtually ensures widespread adoption of the NT platform. Furthermore, NT is built to be portable. By creating a hardware abstraction layer, Microsoft helps make differences in hardware platform a non-issue to the network operating system. back

 UNIX: -

 UNIX is a multi-user, multitasking operating system developed by AT&T's Bell Labs in 1971. Originally written in assembly language, and now primarily written in the C programming language, UNIX has been ported (adapted) to every major 32-bit microprocessor in the world. Strictly speaking, the term "UNIX Operating System" refers only to those operating systems that have passed the UNIX standards test of the X-Open Foundation, which owns the UNIX trademark. X-Open acquired the trademark and standards from AT&T, the original creator of UNIX. In practice, "UNIX" refers to any operating system that provides the programs, commands, and programming interfaces normally found on official "UNIX". 

There are two main variants of UNIX, which have roots in the same original source code from the 1970s and 1980s: System V (AT&T) and Berkeley UNIX, whose last version is called 4.4BSD. There is also one important UNIX "work-alike" - Linux - that looks like UNIX to most users and programmers, but has a totally separate origin and shares no source code with official "UNIX". UNIX machines are the predominant network workstations, acting as servers to other machines, although in the past several years many other Network Operating Systems (NOS), such as Novell NetWare, IBM's OS/2 LAN Server, Apple's AppleShare, Banyon Vines, and Microsoft's NT Server, have gained a share of the market and offer file, and print-sharing services to client machines. 

Advantages of UNIX are: - 

Ø        A rich set of small commands and utilities that do specific tasks well - not cluttered up with lots of special options. UNIX is a well-stocked toolbox, not a giant "do-all Swiss Army Knife".  

Ø        Ability to string commands and utilities together in unlimited ways to accomplish more complicated tasks - not limited to pre configured combinations or menus, as in personal computer systems.  

Ø        A powerfully unified file system.  

Ø        A "lean" kernel that does the basics for you but doesn't get in the way when you try to do the unusual.  

Ø        Available on a wide variety of machines - the most truly "portable" operating system.  

Ø        Optimized for program development, and thus for the "unusual" circumstances that are the rule in research.

FEATURES OF UNIX: - 

Ø        UNIX is interactive, multi-tasking and multi-user. 

Interactive means that you give commands at the terminal and it executes them directly. They are not "batched up" for later execution. Also, you are able to interact directly with every program.  

Multi-tasking means that more than one program at a time can be "running" in the computer without interfering with each other. Good multitasking systems, like UNIX, also prevent poorly written programs from crashing the entire system. While only one program is actually using the CPU at any one time, many programs can reside in memory simultaneously and the CPU switches its attention back and forth between them. This happens so quickly in human time that the programs appear to be running simultaneously. UNIX is democratic in that all programs start with equal priority for CPU time, although there are some mechanisms to change this.  

      Multi-user is a direct result of multi-tasking, but also includes the concepts of authentication and access controls, so that users can be given different privileges and have private files. Note also that each user can have several simultaneous login sessions from several different terminals.  

Ø        UNIX has access controls and security.

 In order to allow multiple users to work without interfering with each other, either accidentally or deliberately, UNIX has various methods of controlling access to programs and files. All users must be authenticated by a valid account and password to use the system at all. All files are owned by particular accounts. The owner can decide whether others have read or write access to his files. There is obviously a need for a system manager to configure and maintain these controls.

 For most of their history, personal computer operating systems (DOS, Macintosh, and Windows) have lacked these types of access control, which made them difficult to share for general use. Now we see that personal computers are borrowing from systems like UNIX to add user accounts and file access controls.

Ø        UNIX offers Integral Networking 

It enables you to access the Internet using a variety of tools (items in brackets are the most used tools on Spock, i.e., elm is Spock's default mail program).

      Some of these are: -

Telnet - to connect to other networked workstations and servers 

Ftp (File Transfer Protocol) - to transfer files across the Internet 

Mail - electronic mail [elm, pine] 

News - clients to access USENET News groups [tin, trn] 

Lynx - A Web client to access World Wide Web servers

 Ø        Ability to link programs together

       Some of the most powerful features of UNIX are the ability to link programs together and use programmable utility programs for complicated data manipulations. These types of programs are still primarily command-line oriented.  

The command-line interface will also work over any type of network or telephone link, using any type of dumb terminal or simple computer as the display, so it is more adaptable.

 People who generally use an X-window workstation or terminal can still run all the command-line programs and commands described in these notes from the "shell" or "terminal" window.

 Ø        UNIX has a hierarchical, universal file system. 

Everything is a "file" - data, programs, and all physical devices. Everything is accessed in a consistent manner.  

Entire file system appears as a single large "tree" of nested directories, regardless of how many different physical devices (disks) are included. back

Comparing Windows NT and UNIX System Management

 To many UNIX administrators, the Microsoft® Windows NT® operating system is largely a mystery. The user interfaces, internal architecture, and underlying design of the respective operating systems are very different, and these differences often lead experienced UNIX administrators to dismiss Windows NT capabilities. More often than not, this dismissal is the result of underestimating the strengths of Windows NT relative to the various flavors of UNIX. This project addresses Windows NT topics that UNIX administrators frequently cite.

Ø      BASIC

 Microsoft Windows NT is a server platform that evolved from Windows 3.11 (Windows for Workgroups) into Windows NT 3.51, and then into Windows 4.0. There have been numerous patches and 3 service releases, with another one on the way. It is still a very young operating system, without the maturity of Unix, which has been around for more than 30 years. Windows NT is often dismissed as a "proprietary" operating system because it is only available from a single vendor, unlike UNIX (which is no longer available in its original AT&T form). Windows NT offers a consistent set of services, application interfaces, APIs, and management tools on both Intel x86 and Digital Alpha CPUs on a variety of hardware, ranging from laptops and desktop workstations to multiprocessing, clusterable servers. Developers can write to a single set of unified APIs and have their code run on machines anywhere in this range, from Pentium laptops to large multiprocessor servers.

 Contrast this with the state of the UNIX world, where proprietary hardware is the norm and ISVs must be aware of, and careful with, the API and configuration differences between different versions of UNIX. This diversity also causes problems for data center and desktop managers who must build tools to monitor and manage UNIX configurations that can differ radically--especially since access to source code for tools and applications is normally required to move from one variant to another. For example, a custom management tool built to use kernel parameters exported by Solaris 2.5 won't work on AIX or HP-UX and may not work under Solaris 2.6.

 Ø      MANAGING SECURITY

Every process and object on a computer running Windows NT has its own discretionary Access Control List (ACL); the ACL precisely specifies which entities may, and may not, access the object and what permissions they have. The Windows NT File System (NTFS) allows fine-grained control over permissions on files and directories. Some UNIX systems implement ACLs through add-on security packages.

Ø      MANAGING PERFORMANCE

Performance management normally starts with the gathering of a data baseline that indicates what system performance "normally" looks like. Once a baseline has been established, it can be used to evaluate future performance and estimate future capacity needs.

Windows NT is designed to expose a great deal of performance data. The Windows NT kernel and services export detailed information about processor, memory, disk, and network usage. Add-on services, including SNMP, Netscape's FastTrack and Enterprise web servers, and BackOffice components, may add their own application-specific data to what's available. This data can be collected using the Windows NT Performance Monitor, a single application that can simultaneously collect performance data from any number of network machines, then display it as a graph, format it as a tabular report, or log it for later analysis.

Because Performance Monitor support is integrated throughout Windows NT, administrators can gather a variety of performance data from many machines at once and use the collected data both for instantaneous and long-term monitoring.

Most UNIX variants include some type of kernel-level instrumentation, along with rudimentary tools for monitoring CPU, disk, and memory usage. These tools are generally not as flexible as the Windows NT Performance Monitor: they usually can monitor only one machine at a time, may be limited to text-only displays, lack archiving capability, and can't be expanded to monitor additional components.

 Ø      MANAGING PROBLEMS

Problem management is the process of providing error isolation, diagnostic services, and consolidated system help facilities. With UNIX, the availability and power of problem management tools varies widely from vendor to vendor; by contrast, Windows NT offers a consistent set of tools on all its supported platforms.

Error isolation can be performed through a variety of Windows NT tools. The Performance Monitor can be used to isolate performance and resource usage problems, either by using its alert view to notify when monitoring settings go out of limits or by watching a graph or table view in real time. The Event Viewer logs can be augmented with automated tools (easily written in Visual Basic) which look for particular event types or event codes (for example, an unplanned server reboot or an application I/O failure) and send notifications when necessary. The Windows NT Network Monitor may be used to capture and analyze network traffic, which is often valuable when isolating protocol or routing problems. Some of these capabilities are available as third-party UNIX products.

Hardware and software diagnostics can be performed locally or remotely. Windows NT includes a simple diagnostic tool that can be used to pinpoint resource conflicts. Most hardware vendors include their own custom set of diagnostic tools as well. Microsoft's Systems Management Server 2.0 package provides a complete set of remote diagnostic tools that can be run on any workstation or server from a central management console. In addition, individual hardware vendors often offer low-level diagnostic tools, which may be run using remote management packages.

Help is an often-overlooked capacity, although administrators and users frequently need it. A good help system will answer users' questions before they call a help desk or other support resource. Windows NT includes a comprehensive set of help files for all its system software and components, including a full-text index that allows natural-language queries. UNIX vendors all offer man pages; many also ship proprietary help viewers with indexing and searching capabilities, and some have started to include HTML versions of their documents.

Ø      MANAGING STORAGE

Storage management means putting things in various kinds of persistent disk, tape, or optical storage, indexing their locations so specific data can easily be retrieved, and providing ways to monitor the use of storage space.

Windows NT includes software that provides disk mirroring and stripe sets; these capacities often require special-purpose disk controllers on UNIX machines, though some vendors support software RAID directly or through add-on products. Windows NT and UNIX both support hardware RAID controllers, but UNIX vendors tend to use proprietary controllers, meaning that administrators in multi-vendor sites have to remember the often-arcane details of configuring each controller type. Windows NT-based servers can use a variety of available controllers, so sites can standardize on the controllers that suit them best.

File location and indexing can be controlled through the conventional Windows Explorer interface. Windows NT also automatically monitors all physical disks and warns administrators when the percentage of free space falls below a preset threshold; this capacity normally requires a custom shell script under UNIX.  back

 CONCLUSION 

Windows NT and UNIX interoperability is prerequisite in today's increasingly common heterogeneous computing environments. From the network, data, applications, and management layers, tools and technologies to allow these systems to inter-operate are either built into Windows NT or are readily available from increasing numbers of third parties. Allowing customers to benefit from their investment in UNIX systems, while taking advantage of the rich services that the Windows NT platform offers, is a high priority for Microsoft. Customers will see continued advances in these technologies, making it even easier to deploy and manage heterogeneous UNIX and Windows NT-based networks. back

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