Local area network novell netware. General information. Novell developed the NetWare operating system. What did the Novell netware operating system consist of?

Introduction

Modern computer system consists of one or more processors, random access memory, disks, keyboard, monitor, printers, network interface and other devices, that is, it is complex integrated system. Writing programs that monitor all components, use them correctly, and still perform optimally is an extremely difficult task. For this reason, computers are equipped with a special layer of software called an operating system.

operating system, OS (English operating system) - basic complex computer programs, providing control of computer hardware, working with files, input and output of data, as well as execution application programs and utilities. Typically, the operating system is stored on a hard or floppy (system) disk.

When you turn on your computer, the operating system loads into memory before other programs and then serves as a platform and environment for them to work. In addition to the above functions, the OS can perform others, for example, providing a user interface, network interaction, etc.

There are operating systems that use command line for entering commands and running programs using the keyboard, and graphical operating systems. In the latter, the main control device is a mouse or other positioning device.

IN different models A computer can use different operating systems, which differ in RAM resources and provide different levels of service for programming and working with ready-made software.

There are various operating systems for personal computers and servers: OS family Microsoft Windows and Windows NT, Mac OS and Mac OS X, NetWare, UNIX-class systems, and Unix-like (GNU/Linux).

Novell company

Novell is the largest company, which owns, according to various sources, from 65% to 75% of the market for network operating systems for local area networks. Novell is best known for its network operating systems of the NetWare family. These systems are implemented as systems with dedicated servers.

Novell's main efforts were spent on creating a highly efficient server part of the network OS, which, due to its specialization in performing file server functions, would provide the highest possible speed for this class of computers remote access to files and increased safety data. For the server part of its OS, Novell has developed a specialized operating system that is optimized for file operations and uses all the capabilities provided by Intel x386 and higher processors. Users of Novell NetWare networks pay a price for high performance - a dedicated file server cannot be used as a workstation, and its specialized OS has a very specific API, which requires special knowledge, experience and significant effort from developers of additional server modules.

For workstations, Novell produces two proprietary operating systems with built-in networking capabilities: Novell DOS 7, which includes the Personal Ware peer-to-peer networking component, and UnixWare, which is an implementation of UNIX System V Release 4.2 with built-in NetWare networking capabilities. For popular personal computer operating systems from other manufacturers, Novell produces network shells with client functions in relation to the NetWare server.

The NetWare operating system was originally developed by Novell for the Novell S-Net network, which has a star topology and a proprietary server with a Motorola MC68000 microprocessor. When IBM released the PC XT personal computer, Novell decided that NetWare could be easily ported to the Intel 8088 family of microprocessor architectures and would then be able to support virtually every personal computer network on the market.

Understanding NetWare OS

NetWare is a network operating system and suite of network protocols, which are used in this system to interact with client computers connected to the network. The NetWare operating system was created by Novell. NetWare is a closed operating system that uses cooperative multitasking to run various services on Intel x86-based computers. The system's network protocols are based on the Xerox XNS protocol stack. NetWare currently supports TCP/IP and IPX/SPX protocols. NetWare is one of the XNS family of systems. Such systems, for example, include Banyan VINES and Ungerman-Bass Net/One. Unlike these products and XNS, NetWare gained significant market share in the early 1990s and competed with Microsoft's Windows NT, after which other competing systems ceased to exist.

NetWare was based on a very simple idea: one or more dedicated servers connect to a network and provide sharing your disk space in the form of “volumes”. On client computers with operating system MS-DOS system Several special resident programs are launched that allow you to “assign” drive letters to volumes. Users must register online to access volumes and be able to assign drive letters. Access to network resources determined by the registration name.

Users can also connect to shared printers on a dedicated server and print to network printers the same as on local ones.

Despite the fact that in early versions of NetWare all modules of the system were considered unreliable (any malfunctioning module could disrupt the operation of the entire system), it was a very stable system. It is not uncommon for NetWare servers to operate without human intervention for years.

History and versions of the NetWare network operating system

NetWare was created through the work of SuperSet Software, a consulting group founded by friends Drew Major, Dale Neibauer, Kyle Powell, and later member Mac Hurst. This work was based on the results of their studies at Brigham Young University in Provo, Utah in October 1981.

In 1983, Raymond Noorda joined the SuperSet group. The team's initial task was to create a disk-sharing CPM system for networks based on the CP/M hardware that Novell was selling at the time. There was a feeling within the group that CP/M was a doomed platform, and as a result an alternative solution was proposed for the newly released IBM-compatible PCs. The group also wrote an app called Snipes, a text-based game that they used for testing. new network and demonstrating its capabilities. Snipes was the world's first online application and is in fact the predecessor to many popular multiplayer games such as Doom and Quake.

This network operating system was later named Novell NetWare. NetWare uses NCP (NetWare Core Protocol), which is a packet transfer protocol that allows clients to send requests to NetWare servers and receive responses from them. Initially, NCP was tied to the IPX/SPX protocols, that is, the NetWare system itself could only use IPX/SPX for network communication. An embedded system based on the Btrieve DBMS was used to store authentication information.

First software with the NetWare name was released in 1983. It was called NetWare 68 (or Novell S-Net), ran on a Motorola 68000 processor, and used a star topology. This product was replaced in 1985 by NetWare 86, which was written to run on Intel 8086 processors. Upon release Intel processor 80286 Novell released NetWare 286 (in 1986). NetWare 386 followed in 1989 with the release of the Intel 80386 processor. Novell later revised the NetWare version numbering: NetWare 286 became NetWare 2.x, and NetWare became NetWare 3.x.

NetWare 286 2.x

Configuring NetWare version 2 required significant effort: any changes required recompiling the kernel and rebooting the system. Recompiling and replacing the kernel required the alternate use of 20 floppy disks. NetWare administration was done using text utilities such as SYSCON. NetWare 2 used the NetWare file system File System 286, or NWFS 286.

NetWare 3.x

NetWare version 3 was simplified by building on a modular basis. The functions of the operating system were performed by separate software modules - NetWare loadable modules (NLM), which could be loaded both at system startup and as needed after startup. This architecture made it possible to add necessary functions to the system, such as antivirus protection, backup, support for long file names (at the time, file names in the common MS-DOS were limited to 8 name characters and 3 name extension characters), or support for Macintosh files. NetWare was still managed through text-based utilities. NetWare 3.x introduced a new file system that was the default on all NetWare systems prior to NetWare 5.x, Netware File System 386, or NWFS 386.

NetWare originally used the Bindery service for authentication. It was a system in which all user permissions and security data were stored separately on each server. When there were multiple servers on the network, users had to register with each of those servers separately, and each server had to maintain its own list of users with access rights.

NetWare 4.x

Version 4 introduced the Novell Directory Service (NDS) in 1993 - the Bindery service was replaced by a global directory service that described the entire network infrastructure and was managed from a single point. This meant that a user only needed to authenticate to NDS once to access resources on any server in the directory tree structure. Thus, users could access network resources regardless of which server these resources were located on. Version 4 also introduced a number of useful features and utilities, such as Novell Distributed Print Service (NDPS), Java support, and RSA public/private encryption.

NetWare 4.1x

NetWare 4.11 (intraNetWare) included a number of improvements that made it easier to install and manage the operating system, as well as make it faster and more stable. This version also included the first fully 32-bit client for Microsoft Windows workstations and the NetWare Administrator Utility (NWADMIN or NWADMN32), a graphical NetWare administration utility. At that time, Novell still kept its system tied to the IPX/SPX protocol stack, since NCP was only supported with this stack. However, due to the increased popularity of TCP/IP, NetWare 4.11 included a number of components and utilities that made it possible to create intranets and connect local networks to the Internet. The operating system included tools for connecting IPX workstations to IP networks, such as an IPX/IP gateway. For the first time, Novell included the Webserver application, which made it possible to organize websites based on NetWare servers. This version also began the integration of Internet technologies, for example, by implementing the DHCP and DNS protocols on the NetWare platform.

At the same time, Novell intensified efforts to integrate its products with the NDS directory service. Postal system GroupWise has been integrated with NDS, and Novell has released a number of other directory-enabled products: ZENworks, BorderManager, Novell Modular Authentication Services, and others.

NetWare 5.x

With the release of NetWare 5 in October 1998, Novell recognized the critical role of the Internet and made NCP based on supporting the TCP/IP stack rather than IPX/SPX. The IPX/SPX protocol stack was supported, but TCP/IP began to play the role of the main stack. Most Novell and other companies' utilities had to be rewritten to work with TCP/IP rather than IPX/SPX. With NetWare 5, the first version of the graphical Java administration console, ConsoleOne, was shipped, which was supposed to be used in conjunction with the NWAdmin utilities.

NetWare 5 was released at a time when NetWare's market share was declining (in Western markets) as NetWare servers were replaced by Windows servers N.T. It was also released Last update for the NetWare 4 operating system - NetWare 4.2.

Latest version NetWare 5 became version 5.1. NetWare 5.x included many new components, including support for SAN and clusters, the new NSS (Novell Storage Services) file system, which replaced the traditional file system NWFS, Certificate Service, IBM WebSphere, Media Services, Web Search Services, Oracle 8, Novell SQL, Infrastructure Service public keys(PKIS) and others.

NetWare 6.x

With the release of NetWare 6 in October 2001, changes continued: improved support for symmetric multiprocessing (SMP - improved support for multiple processors in a single server), iFolder (a component that allows automatic, intelligent synchronization of files of the specified local folder iFolder with iFolder server for subsequent provision of secure universal access to these files on the local network and over the Internet), iManager (a web-based administration utility for NetWare and other products), Native File Access Pack (NFAP - a component that provides access to NetWare server resources to Windows clients , Macintosh and UNIX-like systems using their respective network protocols), NetDrive (a utility that allows you to assign drive letters to HTTP and FTP resources, as well as iFolder servers), and the default web server has been changed from Netscape Enterprise Server to Apache. Also the Btrieve database (used with previous versions NetWare) has been replaced by Pervasive SQL.

Open Enterprise Server

After NetWare 6.5, Novell released the operating system in 2003 Open system Enterprise Server (OES), in which users can choose the operating system kernel - NetWare or Linux. This integration comes shortly after Novell's acquisition of Ximian and German GNU/Linux vendor SuSE. It is believed that Novell is shifting its focus away from NetWare and porting applications to GNU/Linux. Although Novell officially denies this and states that it will develop both NetWare and Linux.

OES 2 was released on October 8, 2007. It included NetWare 6.5 SP7 and the new Linux-based SLES10.

Performance

NetWare dominated the network operating system market from the mid-80s to the late 90s due to its extremely high performance compared to other network operating systems. Most benchmark tests at the time indicated a performance advantage of between 5:1 and 10:1 over products from Microsoft, Banyan, and others. The results of one benchmark test were particularly interesting: a NetWare 3.x system with NFS services running over TCP/IP protocols (not NetWare's native IPX protocol) was compared with an expensive dedicated Auspex NFS server and with a SCO Unix server with running services NFS. NetWare NFS performance outperformed both NFS systems that were part of their respective operating systems and was twice the performance of SCO Unix NFS on the same hardware.

There were several reasons for NetWare's performance.

File services instead of disk services

During the development of the first version of NetWare, almost all data stores in local networks worked based on the model disk server. This meant that the client computer, in order to read a block of the file, had to make the following requests over a relatively slow local network.

2. Continue reading the next directory blocks until a directory block containing the data of the file you are looking for is found (there could be many such directory blocks).

In NetWare, built on the file services model, client interaction occurred at the level file interface API.

1. Send a request to open a file (if this file has not yet been opened).

2. Send a request for the required data in this file.

All directory search operations to determine the location where the required data is physically located on the disk were performed with high speed locally on the server.

By the mid-1980s, most network operating systems began using the file services model instead of the disk services model. Now there is a return to a disk services model, for example in a SAN.

Efficiency of the NCP Protocol

Most network protocols used during NetWare's development did not rely on the network to deliver messages reliably. Typically, a client's file read operation would be performed as follows.

2. The server confirmed receipt of the request.

3. The client confirmed receipt of the confirmation.

4. The server sent the requested data to the client.

5. The client confirmed receipt of the data.

6. The server confirmed receipt of the confirmation.

The NCP protocol was based on the concept of reliable delivery of packets by the network in most cases. Therefore, the response to the request served in most cases as confirmation. An example of a client read request in this model.

1. The client sent a request to the server.

2. The server sent the requested data to the client.

All requests contained a sequence number, so if the client did not receive a response within the specified time, it would resend the request with the same sequence number. If the server has already processed this request, it resends the cached response. If the server did not have time to process the request, it would send a “positive acknowledgment.”

The result of using this model " reliable network“There was a two-thirds reduction in network traffic and associated delays.

A non-preemptive multitasking operating system designed for network services

Version 4.x and earlier versions of NetWare did not support preemptive multitasking, time sharing, virtual memory, GUI user and so on. The processes and services running on NetWare had to work correctly, processing the request and returning control to the operating system within the allotted time. Unlike NetWare operating systems general purpose(UNIX, Microsoft Windows) were based on an interactive model with support for time-sharing mode, when, without control from the operating system, a program could occupy all available system resources. These environments with preemptive multitasking and memory virtualization introduced significant overhead because these systems never had enough resources to handle all requests from all applications. Such systems improved over time by integrating network services more closely with the "general purpose" operating system kernel, but never reached NetWare's level of efficiency. Unfortunately, in the past, when application processes managed themselves, this "trust" often led to system crashes.

Perhaps the main reason for Novell's success in the 80s and 90s was NetWare's superior performance compared to general-purpose operating systems. However, as the power of microprocessors increased, the efficiency value became less and less, and with the advent of Pentium processor the complexity of managing and developing applications for NetWare began to outweigh the benefits of NetWare. The overconfidence of Novell's marketing department and management against the backdrop of the real threat of competitors (NT4 and Microsoft Exchange) was the last straw in the process that ultimately led to NetWare's loss of position.
Conclusion

As is known, the penetration process information technologies in almost all spheres of human activity continues to develop and deepen. In addition to the already familiar and widespread personal computers, the total number of which has reached many hundreds of millions, there are also more and more built-in computing devices. There are more and more users of all this various technology, and therefore computers and Information Systems are becoming more and more friendly and understandable even for a person who is not a specialist in the field of computer science and computer technology. This became possible primarily because users and their programs interact with computers through operating systems. In today's world, a huge number of people have learned to use computers in work, education, and science. In my opinion, a huge role in the process of computerization of the world was played by the developers of operating systems, who made them understandable to everyone without exception.

FS in the MS-DOS section. This is a configuration file that contains information about the drivers used during the FS startup process. The item is available to the supervisor or his equivalent. The NetWare "accounting system" has a very flexible system accounting for resources provided for public use. Using this menu item you can view, and also having certain rights, set up a fee for use...

Copying files, launching programs, changing directories and using extended OS/2 system attributes for files. Write Allows you to write a file. The network operating systems LAN Manager and LAN Server under consideration make it possible to control access to the keyboard and screen of the file server. In a special non-dedicated operating mode, the file server allows users...

They work like single network. With the help of gateways, local networks are also connected to mainframes - universal powerful computers. 4. LOCAL NETWORK OPERATING SYSTEMS Appearance computer networks led to the development of operating systems for personal computers that allow them to work in networks. Such operating systems provide not only the sharing of hardware...

Operating system NET WARE: Purpose of NetWare OS As you know, a network is a collection of computers connected to each other to ensure data exchange and sharing of various resources. Network resources can be printers, files, application programs, etc. To manage the network, special network operating systems are being developed, which in their organization can be divided into peer-to-peer (Peer-To-Peer Network) and with a dedicated file server (Dedicated File Server Network). Features provided to the user: NetWare provides users with the following features: supports file sharing, provides access to network printers, offers tools for working with e-mail, supports various types of DBMS, provides access to file server on the part of workstations operating under different operating systems, it offers tools that allow connecting remote network segments, ensures “transparency” of access of local and remote users to network resources, offers tools for reliable data storage, protects network resources from unauthorized access, supports dynamically expanding multi-segment volumes on multiple disks of a file server, provides tools for managing corporate network resources: a single directory of network resources NDS in NetWare 4.1, provides transfer and processing data using different protocols: SPX/IPX, TCP/IP, NetBIOS, AppleTalk, supports the operation of superservers in a symmetric operating mode (NetWare 4.1 SMP OS). Advantages of NetWare: NetWare has some advantages over its competitor Windows NT Server 3.51. This is the routing of all protocols on the server, remote control the server itself and effective support for client stations running DOS. Moreover, NetWare 4.1 provides support for a number of services required by an enterprise network operating system. For example, NetWare Directory Service (NDS) has become a powerful tool for managing large corporate networks. The security system includes a function to limit the amount of user data on the server volume. This feature is not implemented in Windows NT. NetWare's performance for file operations and network printing services continues to outperform its competitors, especially in large, heterogeneous networks. Compared to other network operating systems, NetWare supports a larger number of client operating environments, including DOS, Windows, OS/2, Macintosh, and UNIX. NetWare is a leader in the number of hardware and software third companies that expand and complement its functionality. The system has more backup and storage capabilities, more management utilities and networking applications than any other operating system. Another advantage of NetWare is that it is easier to find qualified service personnel to maintain it.

Konstantin Pyanzin

A bad peace is better than a good quarrel.

Proverb

Until recently, the relationship between networking giants Novell and Microsoft resembled warfare. The echoes of the cannonade can still be heard. Novell, which once held a dominant position in the network market, was forced under the pressure of Windows NT to switch to forced defensive actions. However, realizing that nothing could be achieved by taking NT hostilely, Novell changed both tactics and strategy. Now she does not deny many of the advantages of NT (however, she does not forget to emphasize the disadvantages network model NT Server). Novell's credo has changed: "The user has the right to choose any solution, and Novell's task is to help integrate this solution into a single network infrastructure."

Microsoft takes a slightly different position. Although the squabble with Novell has subsided noticeably, Microsoft still adheres to the slogan: “Those who are not with us are against us.” However, this position of Microsoft is typical not only for the network area. The company is capable of taking over any software manufacturer, which it periodically does with success. However, something like common sense and acumen cannot be taken away from Bill Gates. He moves to decisive action only when the ground is prepared. This is fully evident in our relationship with Novell. When did the first ones appear? Windows versions NT, Novell with its NetWare dominated the network market. Therefore, willy-nilly, Microsoft was forced to reckon with this strong rival.

POSITION ON THE NETWORK MARKET

Users, especially at first, showed strong dissatisfaction with the positions of Novell and Microsoft. The struggle between network companies provided freedom of choice, but did not provide the opportunity to transparently use both products in the same environment. Here, Mao Tse Tung’s expression “war is good” is least suitable. Thank God, since the days of online wars, a lot has changed for the better. Now the market offers many products that allow one or another to integrate NetWare and Windows. Although things never came to full integration. Most of these products are supplied directly by Novell and Microsoft. Which is not surprising, since no one knows their systems better than them.

Each of the network operating systems has its own trump cards. NetWare has proven itself to be an excellent file and print server. Novell Directory Services (NDS), included with NetWare 4.x, has become an industry standard in enterprise environments. Currently, it essentially has no competitors. In addition, a number of Novell products, most notably the GroupWise document collaboration system and the ManageWise network management system, firmly occupy one of the leading positions in the world. Among the main disadvantages of the NetWare OS, one can highlight the fact that, due to its architecture, it is not the best choice for the role of application server.

Windows NT, in turn, is well suited for application servers and has an advantageous price/performance ratio. It has a good file/print service, although somewhat inferior to the similar service of NetWare 4.x. In addition, NT Server works great with client sites on Windows based 95 and Windows NT Workstation. NT has a convenient user interface, a lot has been written for it interesting applications. Even Novell admits that Windows NT Workstation-based client PCs are very good in a corporate environment. But NT networks have a big drawback - they use an archaic domain system. It is poorly suited for distributed and enterprise networks and cannot be compared to NDS. In fact, the domain system is the workgroup level.

Historically, before NT, NetWare dominated the networking market, so enterprise customers rarely agree to change their entire network architecture for NT. Moreover, facts show that, despite the active promotion of NT, interest in NetWare does not wane. A very pressing question is how to use in one environment positive traits both network operating systems. There are several options here. It all depends on the required degree of integration.

FOCUS CALLED NWLINK

When Microsoft released the first version of Windows NT Advanced Server 3.1 in 1993, it announced that it would support NetWare. Many users were unpleasantly surprised by how Microsoft interpreted the term "support". NT 3.1's only component for communicating with NetWare was the NWLink IPX/SPX Compatible Transport protocol. This is just a protocol, and nothing more. By itself, it did not allow access to NetWare network resources from NT, as well as access to NT disks from NetWare clients. NWLink made it possible for client-server applications to communicate using the IPX/SPX protocol. In particular, it was possible to install an Oracle DBMS on a NetWare server, and then work with it from a client machine running Windows NT. Nevertheless, the NWLink protocol is still actively used as a transport, including by client software for communicating with NetWare networks.

CLIENT SOFTWARE AS A LINK

The easiest way to solve the problem is to allow NetWare and NT Server to operate independently of each other. They are administered and managed separately, using their own means. To work with NetWare and NT Server, two programs are installed simultaneously on client computers: client software for the NetWare network and client software for the Microsoft network. These programs have a certain degree of integration with each other: the user only needs to enter the login name and password once to get into both networks.

Windows 95/NT Workstation operating systems natively include the Client for Microsoft Networks client software for the Microsoft network, and therefore never have problems accessing the NT server. As for client software for the NetWare network, the situation is somewhat different.

Included with Windows 95 Microsoft client Client for NetWare, which provided a fairly convenient service for NetWare 3.x and NetWare 4.x networks (in BINDERY emulation mode). However, it did not support the rapidly growing Novell NDS directory service (on NetWare 4.x networks). Only a few months after the release of Windows 95 by Microsoft A new client for NetWare was released that allows you to use NDS. However, this client had serious limitations: for example, some NetWare utilities did not work with it. In addition, it did not provide the ability to log into multiple NDS trees at the same time. In fact, the client served only as a means of logging into the NetWare network (at least NetWare 4.x).

Novell provided its own client option called NetWare Client for Windows 95 (shipped free), which eliminated all the limitations inherent in the client for NetWare from Microsoft. This client allows you to register in several NDS trees at once, has convenient management utilities and many other useful functions.

Something similar happened in the operating room. Windows system N.T. Microsoft has prepared two types of client software for the NetWare network: Windows NT Workstation has Client Service for NetWare (CSNW), and Windows NT Server has Gateway Service for NetWare (GSNW). The GSNW product includes all the functionality of CSNW and adds some of its own.

Windows NT 3.5 came with a CSNW (or GSNW) client that did not support NDS, but worked with NetWare 3.x and NetWare 4.x (in BINDERY emulation mode). Beginning with Windows NT 4.0, client software interacts with NDS, but with limitations. The CSNW/GSNW client does not have NetWare network management utilities, and at the same time, Novell utilities for Windows NT cannot run through it. A user can only log in to one NDS tree. However, the CSNW/GSNW client played an important role because, at the time of its release, other tools for interacting with the NetWare network Windows environment There was no NT.

When the new Novell IntranetWare/NetWare 4.11 operating system was released in late 1996, users were perplexed to discover that it did not include client software for Windows NT. The first version of such a client appeared only a few months later, and since then it has been updated several times. Now this software is called IntranetWare Client for Windows NT and is available free of charge. Novell managed to implement many new ideas and technologies in it. Of course, the client implements registration in several NDS trees at once, but that’s not all; for example, it can be updated automatically. Especially for Windows NT, Novell rewrote the main NetWare system utilities, in particular NetWare Administrator for Windows NT.

Perhaps one of the most remarkable components of IntranetWare Client for Windows NT is Novell Workstation Manager. To take advantage of local Windows NT resources, users must be authenticated at boot time by the local Security Access Manager (SAM). With Novell Workstation Manager, an administrator can create a Workstation object in the NDS tree and then associate NDS user, group, and container budgets with that object (made possible by the NDS Schema extension). As a result, the administrator does not have to deal with NT domains to manage local users. When NT boots, the IntranetWare client prompts you for your name, password, NDS tree, etc., replacing the standard Windows NT prompt. When you enter the specified parameters, the client determines whether the user is associated with the Workstation object in the NDS tree. If this is the case, the IntranetWare client automatically creates a local user budget (if it does not exist in the system), and automatically deletes it when finished. This frees the administrator from having to create local budgets on each Windows NT workstation. With one NetWare Administrator utility, it manages all NetWare network resources and Windows NT workstations.

In addition to the Novell Workstation Client, the IntranetWare Client for Windows NT (as well as the Windows 95 client) includes a very useful program Novell Application Launcher (NAL). NAL simplifies the administration of network applications. With NAL, an administrator can create an Application object for any network application in the NDS tree and then associate it with specific users. After setting up NAL, the user, having logged into the Windows client system, will receive a NAL desktop, where this program will already be there. In this case, it does not matter which specific machine the user is sitting at, he will encounter the same configuration everywhere. NAL settings are managed through NetWare Administrator. In addition, NAL contains the so-called delta installer for forced distribution to workstations and software updates over the network.

GATEWAY BETWEEN MICROSOFT AND NETWARE NETWORKS

Microsoft Gateway Service for NetWare software included with Windows composition NT Server allows you not only to perform CSNW client functions, but also to configure Windows NT Server as a gateway between Microsoft and NetWare networks. Through it, Microsoft network users get transparent access to the NetWare service. As a result, there is no need to install NetWare network software on client sites. In order for the gateway to perform the tasks assigned to it, the administrator must create budgets for the NTGATEWAY group and a user of this group on the NetWare servers. This user must have the necessary access rights to files and print queues. All calls to the NetWare server by Microsoft network clients (regardless of their number) will be made on behalf of this user. On the gateway, the NetWare network resource will be mapped to the gateway's local resource. For Microsoft network clients, the NetWare resource will be visible as a gateway resource. Figure 1 shows an example of such a solution. The root directory of the NetWare NW2 server's SYS volume is visible on the NTGT as the local S: drive. In turn, the S: drive is allocated as a network resource \\NTGT\NW. The KOKA client maps this resource to the local logical drive T:.

Picture 1.
By using the Gateway Service for NetWare, Microsoft network clients see NetWare resources as NT server resources.

The Gateway Service for NetWare solution is useful for networks that have low-power PCs that do not allow both NetWare and Microsoft network clients to be installed simultaneously. Unfortunately, this approach has many disadvantages. First, GSNW creates a large load on the NT server. Secondly, all Microsoft client connections are made on behalf of one user in the NTGATEWAY group. Thus, it is almost impossible to differentiate access rights to network resources. Third, a gateway failure will result in a complete loss of connections from all Microsoft clients to NetWare resources. At the same time, the tasks of administering both networks become significantly more complicated. Therefore, this solution has found very limited application.

EMULATION OF ANOTHER SERVICE

Windows NT Server includes File and Print Services for NetWare (FPNW), which allows NT Server to act as a NetWare 3.12 server. This allows PCs running NetWare client software to see NT servers. The administrator not only has to manage NT domains and servers, but also configure the FPNW service, in particular, allocate one of the NT directories as the SYS volume of the NetWare server, assign other NetWare volumes, create supervisor and NetWare user budgets, and determine user access rights to NetWare network resources etc.

Two different server platforms (NT and NetWare) will run on the same physical server. They are controlled by different means. If access to NT files is controlled Explorer program(File Manager in Windows NT 3.x), then in NetWare - FPNW utilities. If a NetWare volume is created based on a directory in the NTFS file system, then access to files is additionally limited by user access rights to these files, i.e., in addition to FPNW tools, you will also have to use NT tools.

Access rights to a NetWare service can only be assigned to users and groups whose budgets have previously been created in the NT domain.

It is clear that the NetWare emulation service in the NT environment greatly complicates network administration. The performance of FPNW compared to real NetWare 3.12 is significantly lower. The lack of NDS support and emulation prevents FPNW from being considered a serious solution for network integration. However, in some cases, using FPNW makes it easier to integrate low-power and diskless NetWare stations into a mixed NetWare/Microsoft environment.

SERVICE SYNCHRONIZATION

A very interesting technology on the path to full interoperability between Microsoft and NetWare networks is service synchronization. It implies that individual NetWare and NT network resources, primarily user and group budgets, are periodically brought into line with each other (synchronized). This approach means that to manage the resources of a mixed network, it is enough to use (ideally) the utilities of only one system.

Microsoft's Directory Service Manager for NetWare (DSMN) provides periodic synchronization of budgets between an NT domain and NetWare 2.x and 3.x servers (budgets are called accounts in Microsoft terminology). After synchronization, users have the same usernames and passwords on both networks. The synchronization operation goes from the NT domain to the NetWare servers. That is, when changes are made to the user's budget on the NetWare server, the NT system will not notice this. Moreover, after synchronization starts, the NetWare budget will return to the initial state. NT user and group budgets can be synchronized with individual or all NetWare servers in a given NT domain. DSMN allows you to run a trial synchronization to see what budgets will look like on a NetWare server. In addition, the synchronization operation can be run on NetWare servers that are temporarily unavailable on the network. Once communication is restored, budgets on these servers will be automatically updated.

The main disadvantages of DSMN include the lack of support for NetWare 4.x and NDS, and the fact that synchronization can only be performed in the direction from the NT domain to NetWare servers. And since a large network can have multiple domains, administration problems are not greatly alleviated.

Novell has released a synchronization tool called Novell Administrator for Windows NT (NAdminNT) that is delayed, but it is much more powerful than Microsoft's similar product. (It should not be confused with NetWare Administrator for Windows NT, which is an NDS management console.)

Distinctive features of NAdminNT are:

the ability to manage NDS and budgets for individual or all NT domains from one NetWare Administartor console;
migration and integration of NT budgets into NDS and NDS budgets into NT domain(s);
using templates when creating budgets in NDS and NT domains.

All of these capabilities are enabled by associating user budgets, local and global NT groups with NDS objects. The administrator no longer needs to use the User Manager for Domains utility of the Windows NT operating system. The product allows you to transfer information not only from NDS to NT, but also from NT to NDS (although with limitations).

Novell Administrator for Windows NT contains five components:

NDS schema extensions;
NetWare Administrator snap-in modules;
integration utility IGRATE.EXE;
NDS Event Monitor;
NDS object replication service.

NDS schema extensions allow you to add new object types to NDS, as well as new properties for existing NDS objects. To manage NT objects through NDS, NAdminNT introduces the following objects into the NDS schema:

NT domain;
NT working group;
NT user;
global NT group;
local group NT;
hybrid NT user (this is obtained by synchronizing the existing NDS user budget and the existing NT user budget).

NetWare Administrator plug-ins allow you to manage NT objects through the console, and the integration utility allows you to create NDS budgets from NT budgets, and vice versa, as well as synchronize NDS and NT budgets.

NDS Event Monitor and NDS Object Replication Service (ORS) work closely together to provide automatic synchronization (unlike the integration utility) of NDS objects and NT budgets (see Figure 2). However automatic update can only go in the direction from NDS objects to NT budgets.

Figure 2.
Automatic synchronization in Novell Administrator for Windows NT.

The NDS Event Monitor (NDSDM.NLM) is hosted on the NetWare server that contains the master replica of the NDS partition. To improve fault tolerance, NDS Event Monitor is also recommended to be installed on NetWare servers that contain read/write replicas.

The NDS object replication service is installed on the NT primary domain controller (PDC), and for fault tolerance - on backup domain controllers (BDC).

When changes are made to NT objects in the NDS tree (for example, when creating a new user's budget), the event monitor tracks them, and it understands when the changes affect NT objects and when they do not. Next, the filtered information is transferred to the NDS object replication service located on the NT server (via IntranetWare for Windows NT). The OSR then sends the necessary requests to the SAM Security Budget Manager. If the PDC is down, Event Monitor will automatically forward the changes as soon as communication with the PDC is restored.

Novell Administrator for Windows NT can be downloaded free of charge from Novell's Web server ( http://www.novell.com).

Unfortunately, all synchronization tools have the disadvantage that they only support synchronization of individual network services, usually at the level of user and group budgets. Administrators still have to use other system utilities, in particular to grant access rights to network resources. In addition, automatic updating occurs only in one mode. For example, if some administrators of a large network use Microsoft system utilities to manage NT, and some use Novell Administrator, then the information may be inconsistent and, as a result, it will need to be corrected manually.

HIGHLIGHT OF THE SEASON - NDS FOR NT

After much delay, Novell released NDS for NT, making all NDS features available on the NT platform. To be fair, it should be said that the delay was caused primarily by Microsoft's extremely negative attitude towards this idea. This product has already been presented in the previous issue of LAN, so we will limit ourselves to considering its main features.

NDS for NT replaces NT primary (PDC) and backup (BDC) domain controllers dynamic library AMSRV.DLL, responsible for accessing the SAM database, to its own. In addition, IntranetWare for Windows NT clients are installed on NT domain controllers. After this, all calls to the SAM database are redirected through the new SAMSRV.DLL and the IntranetWare client to the NDS database. When installing NDS for NT, the administrator specifies those NT budgets that will be transferred to NDS. New object types are created for NT budgets in NDS by extending the NDS schema and using NetWare Administrator utility plug-ins.

Thus, all the functional power of NDS is completely transparently extended to NT. System utilities NT and application programs will not notice the difference between the native SAM and the NDS database when accessing NT budgets. NT users and groups can be managed either through NT or through a single NetWare Administrator console. Moreover, from the console you can administer all NT domains (or, if desired, only certain ones), and then there is no need to establish trust relationships between domains. The complex task of domain management is greatly simplified by functionality NDS. In addition, when using NDS for NT, network fault tolerance increases. For example, you cannot create a new user budget in the standard NT schema if the PDC is not functioning. This is not necessary here because the backup controllers communicate transparently with NDS.

NDS for NT can be uninstalled at any time. In this case, you can choose to return the SAM database to its original state or update it to reflect changes made in NDS.

The disadvantages of the current version of NDS include the inability to manage other NT resources through NDS, except for user and group budgets. In particular, you have to use NT utilities to set access rights to network resources. Unlike other NetWare and NT integration tools released by Novell, NDS for NT is not free, although it is relatively inexpensive.

THE FUTURE OF INTEGRATION TOOLS

It seems that Microsoft has stopped worrying about the problems of integrating NetWare and NT. Recognizing the shortcomings of the NT domain system, she concentrated her efforts on developing a directory service Active Directory, which should appear as part of Windows NT 5.0. At the same time, Microsoft is doing its best to prevent the transfer of NDS to the NT platform. When the first version of NDS for NT was released, a real scandal erupted: Microsoft refused to support systems where this product was installed, inventing completely untenable arguments. However, then the company was forced to back down: it only does not support code written by Novell.

Most likely, the first versions of Active Directory will be uncompetitive. This conclusion suggests itself if you take a closer look at the history of software development. Microsoft has demonstrated this many times in its products. And not just Microsoft. When Novell released the first version of NDS in 1993, it simply didn't work. It took several years before NDS became attractive.

Microsoft has no plans to port Active Directory to other platforms. She believes she can make other companies dance to her tune. And, probably, with good reason.

Novell's situation is completely different. It is forced to reckon with other players in order to maintain its place in the network market. It offers its directory service as the basis of a modern network infrastructure. Novell has entered into agreements with leading software vendors to port NDS to various versions of UNIX and even OS/390. NDS implementations are already available for SCO UnixWare and Caldera OpenLinux. But Microsoft is not among the interested partners. Therefore, Novell is forced to move NDS to NT itself and with the opposition of Microsoft. Novell plans to develop NDS for NT, in particular to solve the problem of administering access to NT files and printers, and also to completely transfer NDS to NT, as is done in UNIX.

Konstantin Pyanzin is a LAN columnist. He can be contacted at:

NetWare is a network operating system and a set of network protocols that are used in this system to interact with client computers connected to the network. The NetWare operating system was created by Novell. NetWare is a closed operating system that uses cooperative multitasking to run various services on Intel x86-based computers. The system's network protocols are based on the XNS protocol stack. NetWare currently supports TCP/IP and IPX/SPX protocols. NetWare is one of the XNS family of systems. Such systems, for example, include Banyan VINES and Ungerman-Bass Net/One. Unlike these products and XNS, NetWare gained significant market share in the early 1990s and competed with Microsoft's Windows NT, after which other competing systems ceased to exist.

NetWare was based on a very simple idea: one or more dedicated servers connect to a network and share their disk space in the form of “volumes.” On client computers running the MS-DOS operating system, several special resident programs are launched that allow you to “assign” drive letters to volumes. Users must register online to access volumes and be able to assign drive letters. Access to network resources is determined by the login name.

Users can also connect to shared printers on a dedicated server and print to network printers the same way they print to local printers.

Story

NetWare was created as a result of the work SuperSet Software- a consulting group founded by friends Drew Major, Dale Neibauer, Kyle Powell and later Mark Hirst, who joined this group. This work was based on their studies at Brigham Young University in Provo, Utah in October 1981.

This network operating system was later called Novell NetWare. NetWare uses NCP (hello, NetWare Core Protocol), which is a packet transfer protocol that allows clients to send requests to NetWare servers and receive responses from them. Initially, NCP was tied to the IPX/SPX protocols, that is, the NetWare system itself could only use IPX/SPX for network communication. An embedded system based on the Btrieve DBMS was used to store authentication information.

The first software product bearing the NetWare name was released in 1983. He called NetWare 68(or Novell S-Net), ran on a Motorola 68000 processor and used a star topology. This product was replaced in 1985 by NetWare 86, which was written to run on Intel 8086 processors. Following the release of the Intel 80286 processor, Novell released NetWare 286(in 1986). In 1989, after the release of the Intel 80386 processor, it followed NetWare 386. Novell later revised the NetWare version numbering: NetWare 286 became NetWare 2.x, A NetWare became NetWare 3.x.

NetWare 286 2.x

Configuring NetWare version 2 required significant effort: any changes required recompiling the kernel and rebooting the system. Recompiling and replacing the kernel required the alternate use of 20 floppy disks. NetWare administration was done using text-based utilities, such as SYSCON. NetWare 2 used a file system NetWare File System 286, or NWFS 286 .

NetWare 3.x

NetWare version 3 was simplified by building on a modular basis. The functions of the operating system were performed by separate software modules - NetWare loadable modules(NLM), which could be loaded both at system startup and as needed after startup. This architecture made it possible to add necessary functions to the system, such as anti-virus protection, backup, support for long file names (at that time, file names in the common MS-DOS were limited to 8 name characters and 3 name extension characters) or support for Macintosh files. NetWare was still managed through text-based utilities. NetWare 3.x introduced a new file system that was the default on all NetWare systems prior to NetWare 5.x - Netware File System 386, or NWFS 386 .

NetWare originally used the service for authentication Bindery. It was a system in which all user permissions and security data were stored separately on each server. When there were multiple servers on the network, users had to register with each of those servers separately, and each server had to maintain its own list of users with access rights.

NetWare 4.x

NetWare 4.1x

Open Enterprise Server

1.0

After NetWare 6.5, Novell released the operating system in 2003 Open Enterprise Server(OES), in which users can choose the operating system kernel - NetWare or Linux. This integration comes shortly after Novell's acquisition of Ximian and German GNU/Linux vendor SuSE. It is believed that Novell is shifting its focus away from NetWare and porting applications to GNU/Linux. Although Novell officially denies this and states that it will develop both NetWare and Linux.

2.0

OES 2 was released on October 8. It included NetWare 6.5 SP7 and the new Linux-based SLES10.

Performance

NetWare dominated the network operating system market from the mid-80s to the late 90s due to its extremely high performance compared to other network operating systems. Most benchmark tests at the time indicated a performance advantage of between 5:1 and 10:1 over products from Microsoft, Banyan, and others. The results of one benchmark test were particularly interesting: a NetWare 3.x system with NFS services running over TCP/IP (not NetWare's native IPX protocol) was compared with an expensive dedicated Auspex NFS server and with a SCO Unix server running NFS services. NetWare NFS performance outperformed both NFS systems that were part of their respective operating systems and was twice the performance of SCO Unix NFS on the same hardware.

There were several reasons for NetWare's performance.

File services instead of disk services

During the development of the first version of NetWare, almost all data stores on local networks worked based on the model disk server. This meant that the client computer, in order to read a block of the file, had to perform the following requests over a relatively slow local network.

Read the first block of the directory.
Continue reading further directory blocks until a directory block containing the data of the file you are looking for is found (there could be many such directory blocks).
Read blocks of file records until a block containing the data of the desired file is found (there could be many such blocks).
Read the required data block.

In NetWare, built on the file services model, client interaction occurred at the file interface API level. The network protocols used at the time of NetWare's development did not consider reliable delivery of messages by the network. Typically, a client's file read operation would be performed as follows.

The server confirmed receipt of the request.
The client confirmed receipt of the confirmation.
The client confirmed receipt of the data.
The server confirmed receipt of the confirmation.

The client sent a request to the server.
The server sent the requested data to the client.

The result of using this “reliable network” model was a two-thirds reduction in network traffic and associated latency.

Non-preemptive multitasking operating system designed for network services

In the 1990s, intensive comparisons were made between the performance of network file service operations by specialized software on a conventional operating system and the performance of the same operations by a specialized operating system. NetWare was a specialized operating system, not a time-sharing operating system. It was written entirely to handle client-server requests. The system was initially focused on file and print services, but later demonstrated excellent legacy capabilities as a database platform, systems, graphical user interface, and more. The processes and services running on NetWare had to work correctly, processing the request and returning control to the operating system within the allotted time. Unlike NetWare, general-purpose operating systems (UNIX, Microsoft Windows) were based on an interactive model with support for time-sharing mode, where, without control from the operating system, a program could occupy all available system resources. These environments with preemptive multitasking and memory virtualization introduced significant overhead because these systems never had enough resources to handle all requests from all applications. Such systems improved over time by integrating network services more closely with the "general purpose" operating system kernel, but never reached NetWare's level of efficiency. Unfortunately, in the past, when application processes managed themselves, this "trust" often led to system crashes.

Perhaps the main reason for Novell's success in the 80s and 90s was NetWare's superior performance compared to general-purpose operating systems. However, as microprocessor power increased, efficiency became less and less important, and with the advent of the Pentium processor, the complexity of managing and developing applications for NetWare began to outweigh its benefits. The overconfidence of Novell's marketing department and management against the backdrop of the real threat of competitors (NT4 and Microsoft Exchange) was the last straw in the process that ultimately led to NetWare's loss of position.

The concept of the NetWare operating system, its fundamentals, history of creation, factors for achieving high performance. Characteristics of the product line from NetWare 286 2.x to Open Enterprise Server 2.0 and the reasons for Novell losing its leading position.

INTRODUCTION

A modern computer system consists of one or more processors, RAM, disks, keyboard, monitor, printers, network interface and other devices, that is, it is a complex integrated system. Writing programs that monitor all components, use them correctly, and still perform optimally is an extremely difficult task. For this reason, computers are equipped with a special layer of software called an operating system.

Operating system, OS (English operating system) - a basic set of computer programs that provides control of computer hardware, work with files, input and output of data, as well as execution of application programs and utilities. Typically, the operating system is stored on a hard or floppy (system) disk.

There are operating systems that use the command line to enter commands and run programs using the keyboard, and graphical operating systems. In the latter, the main control device is a mouse or other positioning device.

Different computer models may use different operating systems, which differ in RAM resources and provide different levels of service for programming and working with ready-made software.

There are various operating systems for personal computers and servers: Microsoft Windows and Windows NT family operating systems, Mac OS and Mac OS X, NetWare, UNIX-class systems, and Unix-like (GNU/Linux).

FirmNovell

Novell's main efforts were spent on creating a highly efficient server part of the network OS, which, by specializing in performing file server functions, would provide the highest possible speed for remote file access and increased data security for this class of computers. For the server part of its OS, Novell has developed a specialized operating system that is optimized for file operations and uses all the capabilities provided by Intel x386 and higher processors. Users of Novell NetWare networks pay a price for high performance - a dedicated file server cannot be used as a workstation, and its specialized OS has a very specific API, which requires special knowledge, experience and significant effort from developers of additional server modules.

OS conceptNetWare

NetWare is a network operating system and a set of network protocols that the system uses to communicate with client computers connected to the network. The NetWare operating system was created by Novell. NetWare is a closed operating system that uses cooperative multitasking to run various services on Intel x86-based computers. The system's network protocols are based on the Xerox XNS protocol stack. NetWare currently supports TCP/IP and IPX/SPX protocols. NetWare is one of the XNS family of systems. Such systems, for example, include Banyan VINES and Ungerman-Bass Net/One. Unlike these products and XNS, NetWare gained significant market share in the early 1990s and competed with Microsoft's Windows NT, after which other competing systems ceased to exist.

Users can also connect to shared printers on a dedicated server and print to network printers the same way they print to local printers.

History and versions of the NetWare network operating system

NetWare was created out of the work of SuperSet Software, a consulting group founded by friends Drew Major, Dale Neibauer, Kyle Powell, and later member Mac Hurst. This work was based on the results of their studies at Brigham Young University in Provo, Utah in October 1981.

In 1983, Raymond Noorda joined the SuperSet group. The team's initial task was to create a disk-sharing CPM system for networks based on the CP/M hardware that Novell was selling at the time. There was a feeling within the group that CP/M was a doomed platform, and as a result an alternative solution was proposed for the newly released IBM-compatible PCs. The group also wrote an application called Snipes, a text-based game that they used to test the new network and demonstrate its capabilities. Snipes was the world's first online application and is in fact the predecessor to many popular multiplayer games such as Doom and Quake.

The first software product bearing the NetWare name was released in 1983. It was called NetWare 68 (or Novell S-Net), ran on a Motorola 68000 processor, and used a star topology. This product was replaced in 1985 by NetWare 86, which was written to run on the Intel 8086 processor. Following the release of the Intel 80286 processor, Novell released NetWare 286 (in 1986). NetWare 386 followed in 1989 with the release of the Intel 80386 processor. Novell later revised the NetWare version numbering: NetWare 286 became NetWare 2.x, and NetWare became NetWare 3.x.

NetWare 286 2.x

NetWare 3.x

NetWare version 3 was simplified by building on a modular basis. The functions of the operating system were performed by separate software modules - NetWare loadable modules (NLM), which could be loaded both at system startup and as needed after startup. This architecture made it possible to add necessary functions to the system, such as anti-virus protection, backup, support for long file names (at that time, file names in the widespread MS-DOS were limited to 8 name characters and 3 name extension characters) or support for Macintosh files. NetWare was still managed through text-based utilities. NetWare 3.x introduced a new file system that was the default on all NetWare systems prior to NetWare 5.x, Netware File System 386, or NWFS 386.

NetWare 4.x

NetWare 4.1x

NetWare 4.11 (intraNetWare) included a number of improvements that made it easier to install and manage the operating system, as well as make it faster and more stable. This version also included the first fully 32-bit client for Microsoft Windows workstations and the NetWare Administrator utility (NWADMIN or NWADMN32), a graphical NetWare administration utility. At that time, Novell still kept its system tied to the IPX/SPX protocol stack, since NCP was only supported with this stack. However, due to the increasing popularity of TCP/IP, NetWare 4.11 included a number of components and utilities that made it possible to create intranets and connect local networks to the Internet. The operating system included tools for connecting IPX workstations to IP networks, such as an IPX/IP gateway. For the first time, Novell included the Webserver application, which made it possible to organize websites based on NetWare servers. This version also began the integration of Internet technologies, for example, by implementing the DHCP and DNS protocols on the NetWare platform.

At the same time, Novell intensified efforts to integrate its products with the NDS directory service. The GroupWise mail system was integrated with NDS, and Novell released a number of other directory-enabled products: ZENworks, BorderManager, Novell Modular Authentication Services, and others.

NetWare 5.x

With the release of NetWare 5 in October 1998, Novell recognized the critical role of the Internet and made NCP based on supporting the TCP/IP stack rather than IPX/SPX. The IPX/SPX protocol stack was supported, but TCP/IP began to play the role of the main stack. Most Novell and other companies' utilities had to be rewritten to work with TCP/IP rather than IPX/SPX. With NetWare 5, the first version of the graphical Java administration console, ConsoleOne, was shipped, which was intended to be used in conjunction with the NWAdmin utilities.

NetWare 5 was released at a time when NetWare's market share was declining (in Western markets) as NetWare servers were replaced by Windows NT servers. The latest update for the NetWare 4 operating system, NetWare 4.2, was also released.

The latest version of NetWare 5 was version 5.1. NetWare 5.x included many new features, including support for SANs and clusters, the new NSS (Novell Storage Services) file system replacing the traditional NWFS file system, Certificate Services, IBM WebSphere, Multimedia Services, Web Search Services, Oracle 8, Novell SQL, Public Key Infrastructure Service (PKIS) and others.

NetWare 6.x

With the release of NetWare 6 in October 2001, changes continued with the addition of improved support for symmetric multiprocessing (SMP -- improved support for multiple processors in a single server), iFolder (a component that allows automatic, intelligent synchronization of files in a specified local iFolder with the iFolder server for subsequent provision of secure universal access to these files on the local network and over the Internet), iManager (a web-based administration utility for NetWare and other products), Native File Access Pack (NFAP - a component that provides access to NetWare server resources to Windows, Macintosh and UNIX-like systems using the protocols of the corresponding networks), NetDrive (a utility that allows you to assign drive letters to HTTP and FTP resources, as well as iFolder servers), and the default web server was replaced from Netscape Enterprise Server to Apache. Also, the Btrieve database (used with previous versions of NetWare) has been replaced with Pervasive SQL.

Open Enterprise Server

Following NetWare 6.5, Novell released the Open Enterprise Server (OES) operating system in 2003, which allows users to choose between NetWare and Linux operating system kernels. This integration comes shortly after Novell's acquisition of Ximian and German GNU/Linux vendor SuSE. It is believed that Novell is shifting its focus away from NetWare and porting applications to GNU/Linux. Although Novell officially denies this and states that it will develop both NetWare and Linux.

OES 2 was released on October 8, 2007. It included NetWare 6.5 SP7 and the new Linux-based SLES10.

Performance

NetWare dominated the network operating system market from the mid-80s to the late 90s due to its extremely high performance compared to other network operating systems. Most benchmark tests at the time indicated a performance advantage of between 5:1 and 10:1 over products from Microsoft, Banyan, and others. The results of one benchmark test were particularly interesting: a NetWare 3.x system with NFS services running over TCP/IP (not NetWare's native IPX protocol) was compared with an expensive dedicated Auspex NFS server and with a SCO Unix server running NFS services. NetWare NFS performance outperformed both NFS systems that were part of their respective operating systems and was twice the performance of SCO Unix NFS on the same hardware.

There were several reasons for NetWare's performance.

File services instead of disk services

When the first version of NetWare was developed, almost all data storage on local networks operated on the disk server model. This meant that the client computer, in order to read a block of the file, had to make the following requests over a relatively slow local network.

2. Continue reading the next directory blocks until a directory block containing the data of the file you are looking for is found (there could be many such directory blocks).

In NetWare, built on the file services model, client interaction occurred at the file level. API interface.

1. Send a request to open a file (if this file has not yet been opened).

2. Send a request for the required data in this file.

All directory search operations to determine where the required data is physically located on disk were performed at high speed locally on the server.

By the mid-1980s, most network operating systems began using the file services model instead of the disk services model. Now there is a return to a disk services model, for example in a SAN.

Efficiency of the NCP Protocol

Most network protocols used during NetWare's development did not rely on the network to deliver messages reliably. Typically, a client's file read operation would be performed as follows.

2. The server confirmed receipt of the request.

3. The client confirmed receipt of the confirmation.

4. The server sent the requested data to the client.

5. The client confirmed receipt of the data.

6. The server confirmed receipt of the confirmation.

1. The client sent a request to the server.

2. The server sent the requested data to the client.

The result of using this “reliable network” model was a two-thirds reduction in network traffic and associated latency.

Non-preemptive multitasking operating system designed for network services

Version 4.x and earlier versions of NetWare did not support preemptive multitasking, time sharing, virtual memory, graphical user interface, etc. The processes and services running on NetWare had to work correctly, processing the request and returning control to the operating system within the allotted time. Unlike NetWare, general-purpose operating systems (UNIX, Microsoft Windows) were based on an interactive model with support for time-sharing mode, where, without control from the operating system, a program could occupy all available system resources. These environments with preemptive multitasking and memory virtualization introduced significant overhead because these systems never had enough resources to handle all requests from all applications. Such systems improved over time by integrating network services more closely with the "general purpose" operating system kernel, but never reached NetWare's level of efficiency. Unfortunately, in the past, when application processes managed themselves, this "trust" often led to system crashes.

Perhaps the main reason for Novell's success in the 80s and 90s was NetWare's superior performance compared to general-purpose operating systems. At the same time, as the power of microprocessors increased, the value of efficiency became less and less, and with the advent of the Pentium processor, the complexity of managing and developing applications for NetWare began to outweigh the advantages of NetWare. The overconfidence of Novell's marketing department and management against the backdrop of the real threat of competitors (NT4 and Microsoft Exchange) was the last straw in the process that ultimately led to NetWare's loss of position. Conclusion As you know, the process of penetration of information technology into almost all spheres of human activity continues to develop and deepen. In addition to the already familiar and widespread personal computers, the total number of which has reached many hundreds of millions, there are also more and more built-in computing devices. There are more and more users of all this various technology, and therefore computers and information systems are becoming more and more friendly and understandable even for a person who is not a specialist in the field of computer science and computer technology. It became possible, first of all, because users and their programs interact with computers through operating systems. In today's world, a huge number of people have learned to use computers in work, education, and science. In my opinion, a huge role in the process of computerization of the world was played by the developers of operating systems, who made them understandable to everyone without exception.

1. “Administering Novell Netware 6.0/6.5.”, Gaskin D. - St. Petersburg: BHV-SPb, 2003.

2. “Informatics”, Patrushina S.M., Nelzina O.G. and others - Moscow: ICC “MarT”, 2004.

3. “Modern operating systems”, Tanenbaum E., 2nd edition, - St. Petersburg: Peter, 2002.

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