General information. The NetWare operating system was developed by Novell. Network operating system Novel NetWare: basic protocols, services Operating system novell
NOVELL LAN implementation options
General information
The NetWare operating system was developed by Novell. It can be used in any currently common physical structure of a local area network: Token Ring, Ethernet, or ARCnet. Therefore, the network supported by the NetWare network operating system can have bus, ring, and star topologies. Due to the great popularity of the physical structure of Ethernet, the use of Novell Netware for this type of topology is further considered.
The local area network of Novell is a network of bus topology, for the implementation of which Ethernet equipment is used. The main type of transmission medium for LANs is coaxial cable. Ethernet uses two types of coaxial cables - thick and thin. They are similar in their electrical parameters, but differ from each other in diameter and permissible length of the network segment.
"Pure" Ethernet uses a thick coaxial cable, and to connect servers and workstations to it, you need special devices - transceivers (transceivers).
The basic version of the local area network used by Novell is based on thin cables. Sections of a thin cable through special connectors (T-connectors) connect the network cards located in the computers of the local area network.
LAN consists of a file server and workstations included in the network segment.
Note. A network segment is a piece of coaxial cable with computers connected to it. It can be a separate local computer network or part of a network.The maximum length of a network segment is 185 m, but repeaters can be used to connect up to five segments. One segment includes up to 30 workstations.
Recently, the twisted-pair-wire version of the network has become very popular. It provides for connecting workstations to a hub. For example, one hub is able to support the operation of 12 stations located at a distance of up to 120 m from it. Hubs can be connected in cascades and the maximum number of segments in one network can be 1,024.
Thus, the implementation of a local computer network by Novell is possible on two types of topologies: bus and star.
Abroad, preference is given to twisted pair due to its low cost. In Russia, mainly thin coaxial cable is used.
Structural diagrams of LAN on thin cable and twisted pair are shown in Fig. 6.27.
Figure: 6.27. Novell NetWare computer network:
a - on a thin cable; b - twisted pair
File Server Requirements
In a local network with centralized control, a dedicated server plays an important role, which can perform different functions: file server, print server, database server, etc.
The main resource on a Novell LAN is the file server. It hosts the network operating system, databases, and user applications. The file server must be the most powerful computer on the network, as the performance and functionality of the network as a whole depends on it.
To implement a file server, a personal computer with at least 8 MB of RAM is required. It is desirable that the amount of RAM is 16-32 MB, taking into account the possibility of expanding the network. The capacity of the hard drive of the file server - the main shared resource of the network supported by it - should be 500 - 800 MB.
Due to the fact that the reliability of the file server determines the reliability of the entire network, it is necessary to take special measures to protect the information on the hard disk from failures and losses. One such measure is disk mirroring. Two floppy drives are connected to the file server's hard disk controller, and information is written to both disks simultaneously. If one of the drives fails, it automatically switches to the other. But this method still does not save if the controller fails.
The method of duplicating disks provides greater reliability. In this case, two controllers are installed on the file server, each of which serves its own disk. Thus, two independent channels of recording to the hard disk are created. Information on both disks is duplicated. Therefore, if one controller fails, the other begins to work. And the probability of failure of two controllers at the same time is very small.
The inclusion of two file servers in one network segment is also used.
In addition, the file servers are connected to the electrical network via uninterruptible power supplies.
A necessary resource in a local area network is also a printer that provides network printing functions. You can use a separate computer for this role, or you can combine printing functions with the functions of a file server.
Requirements for workstations
A computer performing the functions of a workstation must provide the user with the ability to solve all his applied tasks.
If a workstation is focused only on a network mode of operation, then, in essence, it does not need either a hard drive or floppy disks. It becomes possible to use diskless workstations. The operating system on such a station is loaded remotely from a file server under the control of a read-only memory installed in the workstation's network card.
Diskless workstations are much cheaper than disk ones; working on them eliminates the possibility of a virus entering the network. At the same time, in a LAN built on the basis of diskless workstations, the load on the file server increases dramatically and the possibility of working at the station in offline... Quite naturally, the requirements for workstations are more modest than those for a file server. The majority of users will be quite satisfied with the amount of RAM 8-16 MB and a hard drive with a capacity of up to 650 MB.
The technical characteristics of a LAN are determined by its functional purpose, the complexity of the applied tasks of users and the economic capabilities of an enterprise using a local computer network.
NETWARE NETWORK OPERATING SYSTEM CHARACTERISTICS
Purpose of the NetWare network operating system
The NetWare network operating system can be thought of as a distributed operating system with modules located on a file server and on workstations.
Novell LAN software structure includes the following components: NetWare network operating system kernel, network utilities, workstation network shell.
Core the NetWare network operating system is located on a file server Network Utilities resident in the memory of the file server, but run on workstations. Finally, network shell workstations are loaded and operated on workstations of a computer network as an extension of the main OS installed on the workstation.
The NetWare network operating system is a real-time multitasking operating system. It is designed to work in a centrally controlled local area network. NetWare provides the ability to network one or more file servers. In the course of development, the NetWare operating system has been implemented in several versions.
NetWare network operating system versions
Net Ware 2.x (Net Ware 286) intended to work on servers with a central processor 80286. Under this version, servers could serve up to 100 workstations; it was possible to create disk volumes up to 255 MB and connect up to 32 disks to the server (a volume means a physical area on a file server's hard disk). NetWare 2.x used its own packet interworking protocol, which excluded the possibility of interoperability with other networks. To make even minor changes to the network configuration, it was necessary to stop the server and launch special programs. Latest NetWare 2.2; not currently available.
NetWare Z.x (NetWare 386) was intended to work on servers with 80386, 80486 and Pentium central processors. Servers with this version of the operating system can serve up to 250 workstations. Up to 64 volumes can be installed on one server; up to 32 disks can be concatenated in one volume. Therefore, the volume can be expanded up to 32 GB.
NetWare Z.x is designed to work with a variety of communication protocols, so servers equipped with it can be connected to different networks.
On workstations supported by this version, you can use operating unix systems and Macintosh.
A significant expansion of the functionality of the network operating system was obtained through the introduction of development and launch tools into its composition loadable NetWare modules (NLM). These tools allow you to create database servers and communication gateways.
A variant of the version of NetWare Z.x - NetWare 3.11 is the most popular network product from Novell.
A further development of the NetWare Z.x operating system was the NetWare 3.12 version. It has significantly expanded the set of network drivers, control utilities, added built-in tools email and it is possible to work with compact disc drives (CD-ROM).
NetWare 4.x - the latest version of the NetWare OS family. It is built on the same principles as the previous one, and is also designed to work on servers with 80386, 80486 and Pentium CPUs. The version of this version of NetWare 4.1 includes all the features of the previous version and significantly expands them.
The NetWare 4.1 network operating system connects up to 1000 workstations with MS DOS, Windows, OS / 2, Unix and Macintosh operating systems.
Work with several servers in one network is provided. But unlike previous versions of NetWare, which required user registration on each server, NetWare 4.1 provides access to all resources after registering on at least one server. Network protection is a fundamentally new tool.
The kernel of the operating system is located on the file server, and the rest of its components are located on workstations.
Network operations are implemented using client-server technology. This means that all shared resources are managed centrally through the file server. Resources are available to client workstations only on request, broadcast over the network to the server.
The resources of workstations are available only to users of the stations themselves and are not shared on the network. This service is sometimes referred to as a dedicated file server mode. It provides a high level of data protection on the network. Further material is presented in relation to the network operating system NetWare 4.1. It is assumed that the MS DOS operating system is installed on the workstations of the local computer network.
NetWare structure on file server
The NetWare operating system kernel on the file server is started by the program SERVER.EXE. After terminating the network operating system, you can return to MS DOS. This organization is convenient for debugging and configuring NetWare.
After the kernel is loaded, all other necessary components of the file server software are loaded in sequence.
Work with the hardware is carried out through drivers. NetWare allows you to dynamically load the main drivers - disk device drivers and network adapters.
In addition to drivers, you need programs that perform certain functions to service the server and the network as a whole. Since NetWare is a multitasking operating system, you can run several of these programs. They will work in parallel. During the network operation, they can be downloaded and deleted again.
Netware loadable modules provide management of files stored on a file server, management of databases, network printers and external communication links, and other resources located on the server.
When you install the NetWare operating system on a file server, its hard disk is split into at least two partitions (parts of a physical disk). The first section is reserved for MS DOS and some files that support the launch of the network operating system. The partition size is 3-5 MB. This section is formatted in MS DOS format.
The second partition of the disk is formatted in the NetWare format. It contains the modules of the network operating system, network utilities, service directories and other modules necessary for the operation of the file server and the network.
It also contains databases and files that should be available to users of workstations connected to the network. The structure of the NetWare network operating system is shown in Fig. 6.28.
Note. Services included in a network operating system are software modules that perform specific functions.
Figure: 6.28. NetWare network operating system structure
The operating system uses two main protocols for data transfer - IPX and SPX.
- IPX protocol (Internetwork Packet eXchange - internetwork packet transfer) is the base for Novell NetWare. It defines the format of packets transmitted over the network and the interface to the network software. IPX conforms to the network layer of the open systems interconnection model. At this level, the protocol provides for the exchange of data blocks without first establishing a connection and without subsequent transmission of an acknowledgment to correctly delivered data blocks.
- SPX protocol (Sequenced Packet eXchange - sequential exchange of packets) provides for the establishment of communication between workstations before starting the exchange. SPX ensures that packets are delivered to their destination. An acknowledgment is sent for each received packet, and in case of errors during packet transmission, their retransmission is carried out. The SPX protocol is based on the IPX protocol and is a higher-level transport protocol.
In addition to these two main protocols, nET-BIOS protocol (Network Basic Input / Output System - network basic input / output system). The protocol was developed by IBM and is aimed at transferring data between workstations. Compared to IPX and SPX protocols, it is a higher layer protocol (it performs the functions of the network, transport and session layers). To ensure the operation of this protocol, the NetWare operating system contains a special program called netbios.exe. It is usually used when working with application programs.
The structure of the network shell at the workstation
Network workstations are personal computers. Users working on them have their own set of files and their own operating system: MS DOS, OS / 2, etc. Since the NetWare operating system differs from the operating systems of workstations, the workstations interact with the file server through a special network shell (Fig. 6.29). It is loaded into the workstation's RAM as a task of its operating system when the station is connected to the network.
The shell consists of four resident programs, the main one being the DOS Requester. Its main task is to redirect requests from application programs to access files either to a local drive or to a network drive. If the files are on local drives, then the requestor returns a request to DOS. If the file is on a network drive, then the request is serviced: it is determined from which server, from which volume or directory the file must be read.
Figure 6.29. Workstation network shell structure
For an application running in the MS DOS environment, the requestor emulates the operation of a hard disk. After loading it into the workstation's RAM, the user gets additional logical disks at his disposal. Physically, these disks are not on the workstation, but for programs and for the user they are no different from local hard disks.
Distributed Directory Service (NDS)
NDS Distributed Directory Service- NetWare Directory Service - stores information about all network users, servers and network resources in a special database. Both administrators and network users have access to this database.
All servers on the same network store information about all network resources. It turns out that they use one directory of a complex structure, and a single network space is created for all network users. The user does not know which resource each server supports. He accesses it through NDS using the unique resource name. Any server can provide it with the required resource.
A distributed directory service is made up of objects. Each object has a set of specific properties and values \u200b\u200bthey accept. Information about objects is stored as records in the NDS database.
NetWare directory tree. A directory tree has three main parts: the root (root object), containers, and leaves.
- Root object is at the top-most level of the directory tree hierarchy. It is always the only one, is created when the network is installed and cannot be deleted. This is the top of the tree.
- Containers contain items such as users, servers, disk volumes, and network printers. The containers are given names to help identify the objects they contain. Containers are branches of a directory tree.
There are three types of containers in NetWare 4.1: countries, organizations, departments.
Containers of various types allow you to create tree structures that match the characteristics of specific networks.
Example 6.15. For networks that go outside the country, it is necessary in accordance with the requirements of the standards to have a container a country (Email). It is recommended to store objects belonging to a specific organization or firm in a container organization.In container organization can create containers subdivisions for dividing the network in accordance with the structure of the company.Leaves are part of containers and are always the last level of the hierarchy. Leaves as objects in the directory tree correspond to items such as users, servers, disk volumes, print queues. Leaves cannot contain any objects.
Note. The NDS directory tree is similar to the directory structure of the MS DOS file system. Containers correspond to directories containing files and Other directories, and leaves correspond to files.There are 19 types of objects in NetWare 4.1. Objects can be identified by names and icons.
Usernames in the directory tree. The following scheme is used to identify the user:
sheet name(user) .container name(sheet layout) .container namenext level ... top of the tree.
Example 6.16. User Victor Stoupak (STOUVIC), Fellow of the Department of Information Systems in Economics and Management (ISEM), part of the Faculty of Economics and Management (FEM), St. Petersburg Technical University (SPTU). His full name will look like:STOUVIC. ISEM. FEM. SPTU
The location of the object in the directory tree. The term "context" is used to describe the location of an object in a directory tree.
User context in the directory tree - a list of containers in which it is located. Example 6.17. User context from the previous example: ISEM. FEM. SPTUNetWare file system structure. The file system consists of volumes that represent the disk storage system. Volumes are objects in the NDS directory. They are the highest (root) level in the NetWare operating system disk directory structure. The server can support up to 64 volumes.
Tom - the physical area on the hard disk of the file server within the partition allocated for the disk operating system.The maximum size of a single volume can be up to 32TB. Up to 64 volumes can be organized on the hard disk of the file server. The first volume on the system is always called SYS. It is created when the operating system is installed. It contains the following directory structure:
- SYSTEM- Contains NetWare commands and network supervisor files;
- PUBLIC - Contains NetWare files available to all users;
- LOGIN- directory available to the user after registration in the network;
- MAIL - a directory accessible to all network users for e-mail.
In order to work with the volume, it must be edited. Volumes are mounted when the NetWare server boots. The SYS volume is automatically mounted. Other volumes are mounted using commands in the config file AUTOEXEC.NCF.
Mounting and unmounting a volume can be done from the file server console using the commands mount and dismount.
Note. NetWare volume directories can be referenced in the same way as MS DOS directories, i.e. using routes (paths). Example 6.18. The fully qualified directory name SYSTEM on volume SYS is SYS: SYSTEM. To specify the DATA subdirectory, enter: SYS: SYSTEM / DATA. If the directory is located on the VICTOR server, the link to it will look like this: VICTOR / SYS: SYSTEM / DATA.A special MAP operating system command allows you to simplify the NetWare directory naming scheme and reference directories by drive letters. The MAP command is similar to the PATH command in the MS DOS operating system. It can be used to create access paths to executable files. To do this, the MAP command must be included in the user logon script. When the registration script is executed, all paths and drives will be set automatically.
New directories can be created using the MS DOS MD command or the dedicated NetWare FILER utility.
NetWare also allows you to use the CD and RD commands in MS DOS. We recommend that you separate application and program files and data files when writing to volumes.
PURPOSING BASIC NETWARE COMMANDS
Working with Files and Directories in NetWare
Earlier we mentioned the possibility of using MS DOS commands to work with files and directories in NetWare.
At the same time, there are special commands and utilities of the network operating system that are more reliable than the MS DOS commands.
The NetWare commands used to manage files and directories include: NCOPY, ND1R, RENDIR.
Command NDIR is used to obtain the following information:
- about files and subdirectories of this directory;
- the amount of available and used space in the directory and on the volume;
- about directories and subdirectories, taking into account user rights in the directory.
Command NCORY provides copying of files from one network directory to another. It is more reliable on the network than the MS DOS COPY command.
Command RENDIR used to rename directories.
Basic NetWare Utilities
The network management tools include a fairly large number of different utilities. They are intended for both network users and network administrators in a NetWare environment.
All existing utilities can be divided into four groups:
- command line utilities;
- admin commands;
- server console commands;
- utilities driven by their own menus.
All command line utilities are stored in the SYS: PUBLIC directory and are therefore available to almost everyone on the network. This is secured by the rights to view and read files in the directory for each user.
Admin Commands are accessible only to the network administrator and are therefore stored in the SYS: SYSTEM directory. This directory also contains all loadable network modules, NetWare configuration files, and a special system account file. Access to the directory of ordinary users is undesirable.
The file server is controlled from a keyboard connected to it - the server console. Both local and remote consoles can be used on the network. The special program RCONSOLE allows a user with direct access to the server to enter console commands. This allows you to control the server operating modes, but requires special knowledge and rights to access the console.
Of greatest interest for users working in MS DOS environment are utilities managed own menu. Among them, the NETADMIN, FILER and NETUSER utilities should be distinguished.
Utilities, managed from their own menu, are much more convenient for the end user, since the special components included in them greatly simplify their understanding and, using a system of prompts, "lead" the user to the chosen goal.
The components of such utilities are:
NETADMIN utility. This utility is intended for system configuration. It is available to both a regular user and a system administrator.
Through the main menu, the NETADMIN utility provides the following functions:
- accounting of system information;
- changing the current server;
- getting information about groups;
- obtaining information about users;
- supervisor capabilities.
A user from a workstation can get the necessary information about his network using the NETADMIN utility.
The "supervisor capabilities" menu item is available only to the system administrator and the user with his rights.
Note. On Windows, the NETADMIN utility is performed by the NWADMIN utility.NETUSER utility. The main purpose of the NETUSER utility is to manage routing maps, in which a correspondence is established between a volume on a hard disk and a specific logical drive. It is also used to obtain information about network users and to send messages between workstations on the network.
The main menu of the utility provides access to the following functions:
FILER utility. It is NetWare's premier file and directory utility. The range of tasks that can be solved with its help is determined by the NetWare security system.
The main menu of the utility provides access to the following functions:
The three utilities considered are quite enough to satisfy the needs of an ordinary network user.
It is easy for the user to learn how to work in the network with the help of utilities managed through their own menu, since it is practically no different from working with common software products that have a drop-down menu.
ORGANIZATION OF NETWORK RESOURCES PROTECTION IN NETWARE
Purpose of LAN protection
Like any multi-user system, a local computer network imposes rather stringent requirements for data safety and protection of network resources from unauthorized access.
To create effective protection, it is necessary to develop its strategy. Typically, the security strategy includes restrictions on the user and restrictions on directories and files.
The restrictions imposed on the user include:
Password protection;
Eight types of access rights are set to enforce restrictions on access to files and directories.
Access right - the ability to perform certain operations with data on the network, provided to the user by the network operating system.These rights apply to files and subdirectories within a directory. In addition, special signs can be set for files and directories - attributes (5 types for directories and 14 types for files). Attributes determine the ability to work with files and directories for a particular type of user.
Since the restrictions imposed on the user depend on their type or category, the NetWare operating system determines the categories of network users.
NetWare network users
Before starting to work on the network, each person must determine their user status.
The NetWare operating system establishes four main categories of users: administrator (supervisor), workstation user, operator, auditor.
The main role in the network is played by her administrator... The administrator is responsible for the correct and uninterrupted operation of this network and controls the operation of the entire system. It can enter and delete users, assign access rights, update and reconfigure the entire network.
Workstation users - this is end usersregularly working with the network. They have at their disposal file space, access to shared database resources, access to other networks, and access to network printing.
Network operators - these are the same users with some additional network management capabilities. This can be the management of queues for network printing, the organization of the print server, work in the remote console mode. Remote console means emulation by means of a special file server console program on a workstation.
Auditor -a user who can collect various statistical data about the network and about the events taking place in it, without control by the network administrator-
For convenience, you can combine network users into groups.
Group- a set of users performing a certain class of tasks requiring access to general information.Several user groups can exist on a network, with a manager assigned to each group. The group manager has more capabilities than ordinary users. It can create and delete user groups, include and delete individual users in a group, assign trusteeship rights, and assign manager status to individual users.
Attention! During network setup, only an administrator named SUPERVISOR is created.All other users are created administrator. He assigns them names and passwords.
Each new user, by default, gets the right to use network printing and access to utilities located in the PUBLIC directory.
Supervisor has full privileges on the network. You cannot delete it. He can, in addition, create users with the same rights, which, unlike him, can be deleted.
Remember! In order to work in the network, the user needs know or be able to find out your network name, password and work schedule.This problem is solved by the only directory accessible to the user (after loading the network shell) on the file server - LOGIN.
With the help of the NLIST utility, the user defines the file servers of this network available to him.
Using the LOGIN utility, the user logs on to the network on the selected file server.
Connection during work to another file server is provided by the ATTACH utility.
The LOGOUT utility is used to disconnect from one of the file servers or to log off the network.
Basic NetWare Security
The NetWare operating system provides the network user with four levels of protection:
protection by registration name and password;
protection by the rights of guardianship;
protection of directories by the filter of inherited rights;
protection of directories and files using attributes.
These levels can be used separately or in various combinations.
When creating a certain structure of the LAN, the network administrator must define the groups, the composition of the groups and set the rights for groups and users in files and directories.
Registration name and password protection. This protection is set up by the network administrator using the NETADMIN utility in "supervisor capabilities" mode. With its help, a limit is established on the number of competing connections and the number of allowed entries for an incorrect password. These restrictions are imposed on all users.
The time limit for network access can be set both for individual users and for groups of users.
Attention! The user can always get information about his workstation after connecting to the network using the WHOAML utility.Trustee Rights. Trustee rights are granted for working with files in a specific directory. When obtaining rights in a certain directory, the user automatically gets the same rights in all its subdirectories. Trustee rights can also be assigned to individual files.
You can assign trustee rights to both users and groups. The group right is automatically extended to all members of the group.
The NetWare operating system provides eight types of guardianship rights:
S (Supervisor) - supervisory right;
R (Read) - reading from a file;
W (Write) - writing to a file;
A (Access Control) - access control;
С (Create) - creating new files and directories;
E (Erase) - deleting files and directories;
F (File Scan) - search for files and directories;
М (Modify) - modification of file attributes, renaming of files and directories.
Attention! The supervisory right (S) allows: create, rename and wash subdirectories in a given directory, set guardianship rights and rights filter, restoreany other rights therein.Right access control (A) makes it possible to assign any rights to other guardians. In real network operation, a user is assigned a combination of these rights.
Inherited rights filter (Inherited Rights Filter). Directories and all trustees in subdirectories are affected by a specially installed inheritance filter. As much as possible, the filter includes all trusteeship rights and is abbreviated as:. Each letter corresponds to the initial in the title of the guardian law.
When creating a subdirectory, it is assigned maximum rights, which can be changed later. The inherited rights filter allows you to filter rights only from top to bottom.
You can change the filter using the MAP command or the FILER utility.
Remember! The inherited rights filter is used only to reduce rights. Mask-filtered rights cannot reappear at lower levels of the directory system.Typically, the inherited rights filter is applied to directories that are shared by many network users. By placing restrictions on such directories, the network administrator knows for sure that users will only be able to do work in subdirectories that they are allowed to do.
When the filter is installed, the withdrawn rights are indicated by an underscore symbol.
Example 6.19. When creating the directory, the user inherited the [_RWCEMFA] rights. But the administrator has imposed the mask [_R_ _ _ _F_] on the user's directory. This means that it is allowed to search for files and view information in them in this directory. The filter allows only those rights from the list of maximum rights that are specified in it.The netizen must know their effective rights.
Effective rights- the rights that the user actually gets to this directory and file.To determine effective rights, you need to know:
- the assigned guardian rights of the user;
- assigned guardianship rights for the group;
- filter of inherited rights.
Effective rights.
Remember! When an inherited rights filter is entered, the user is granted effective rights, which is the result of the filter filtering out the inherited rights of the directory. Those rights that match the rights in the filter are passed down. Example 6.21.Permissions inherited from the [_RWCEMF_] directory. Filter inherited directory rights. Effective user rights [_RW _ _ _F _] / Remember! A user with supervisor rights has all rights in the directory system below the one where he was granted this right. It cannot be limited to the lower levels of the directory structure.Viewing, assigning and removing rights. In the NetWare operating system, the user can view their rights in different directories using the NETADMIN utility.
Setting a mask of rights, assigning trustees to directories and changing trusteeship rights are performed using the FILER utility. The same utility allows the user to define their effective rights.
In addition to the menu utilities, you can also use the RIGHTS command line utilities to perform these operations.
The RIGHTS utility provides the following functions:
- assignment of guardianship rights for individual users and user groups;
- deleting a user or a group of users from the list of trustees of this directory;
- removal of custodial rights in the directory;
- displaying a list of trustees for a directory;
- displaying effective user rights in the directory.
Default rights. As mentioned earlier, after installation on the file server of the NetWare network operating system, the SYS: volume and the LOGIN, PUBLIC, SYSTEM, MAIL directories are automatically created.
There is a Supervisor administrator on the network with the password that was set when you first log on to the network.
Automatically defined rights are granted to enable networking. Supervisor gets all rights in all directories, newly created users have all rights in the MAIL directory and search and read rights in the LOGIN and PUBLIC directories.
In the SYSTEM directory, except for the Supervisor administrator, no one has any rights.
Protecting files and directories with attributes. When working in a computer network, you have to share large information files that many users have access to. If the file information is destroyed or distorted, it is almost impossible to restore it to its previous state.
To this end, the NetWare network introduces file and directory attribute protection. Applying attributes gives users the ability to adjust the process sharing his personal files and directories and modifying them.
There are 13 attributes to protect files, but the following six attributes are most commonly used:
Read-Write (Rw) - file for reading and writing;
Read-Only (Ro) - read-only files;
Shareable (Sh) - shared files;
Delete Inhibit (Di) - file deletion is prohibited;
Rename Inhibit (Ri) - file renaming is prohibited;
System File (Sy) - A hidden system file.
Any newly created file gets the Read-Write attributes by default and is an unshareable file.
Remember! File attributes can be set using either the FLAG command or the FILER utility.Nine attributes can be set for directories, the main ones are:
- Normal (N) - normal, no attributes are set;
- Hidden (Н) - hidden directory, after entering the DIR command it is not displayed;
- System (Sy) - hidden directory used by the operating system;
- Rename Inhibit (Ri) - catalog renaming is prohibited;
- Delete Inhibit (Di) - deletion by RD command is prohibited;
- Purge (P) - the directory to be deleted, cannot be restored.
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 complex system. Writing programs that keep track of all the 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 (eng. operating system) - a basic complex of computer programs that provides control of computer hardware, working with files, input and output of data, as well as the execution of application programs and utilities. Typically, the operating system is stored on a hard or floppy (system) disk.
When you turn on the computer, the operating system is loaded into memory before other programs and then serves as a platform and environment for their work. In addition to the above functions, the OS may perform others, for example, providing a user interface, networking, etc.
A distinction is made between operating systems that use the command line to enter commands and launch 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 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: operating systems of the Microsoft Windows and Windows NT family, Mac OS and Mac OS X, NetWare, UNIX-class systems, and Unix-like (GNU / Linux).
Novell
Novell is the largest company, with 65% to 75% of the LAN operating system market, according to various sources. Novell is best known for its NetWare family of network operating systems. These systems are implemented as dedicated server systems.
The main efforts of Novell were spent on creating a highly efficient server part of the network operating system, which, due to specialization in performing the functions of a file server, would provide the highest possible speed of remote file access for this class of computers and increased data security. For the server side of its operating systems, Novell has developed a dedicated operating system that is optimized for file operations and takes full advantage of the capabilities of Intel x386 and higher processors. Users of Novell NetWare networks pay for high performance with a cost - a dedicated file server cannot be used as a workstation, and its specialized OS has a very specific API, which requires special knowledge, special experience and significant effort from developers of additional server modules.
For workstations, Novell releases two proprietary operating systems with built-in networking: Novell DOS 7 with its Personal Ware peer-to-peer component, and UnixWare, which is a UNIX System V Release 4.2 implementation with built-in NetWare capabilities. For popular operating systems of personal computers 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, which has a star topology and a proprietary server with a Motorola MC68000 microprocessor. When IBM released PC XT personal computers, Novell decided that NetWare could be easily migrated to the Intel 8088 family of microprocessor architecture, and then it could support virtually all personal computer networks on the market.
Understanding NetWare OS
NetWare is a network operating system and a set of network protocols that are used in this system to communicate with client computers connected to the network. The NetWare operating system was created by Novell. NetWare is a proprietary operating system that uses cooperative multitasking to run a variety of services on Intel x86-based computers. The network protocols of the system are based on the Xerox XNS protocol stack. NetWare currently supports TCP / IP and IPX / SPX. NetWare is one of the XNS family of systems. Such systems include, for example, Banyan VINES and Ungerman-Bass Net / One. In contrast to these products and XNS, NetWare gained a significant market share in the early 1990s and competed with Microsoft 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 the network and share their disk space in the form of "volumes". On client computers with operating room mS-DOS system several special resident programs are launched that allow you to "assign" drive letters to volumes. Users need to log on to the network to access volumes and be able to assign drive letters. Access to network resources is determined by the registration name.
Users can also connect to shared printers on a dedicated server and print to network printers in the same way as local printers.
Despite the fact that in earlier versions of NetWare all modules of the system were considered unreliable (any module malfunctioning could disrupt the entire system), it was a very stable system. It is not uncommon for NetWare servers to run without human intervention for years.
NetWare Network OS History and Versions
NetWare was the product of SuperSet Software, a consulting group founded by friends Drew Major, Dale Nybauer, Kyle Powell and later Macrom Hirst. 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 group's initial challenge was to create a CPM disk-sharing system for networks based on CP / M equipment that Novell was selling at the time. Within the group, the conviction developed 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 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.
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 and receive responses from NetWare servers. NCP was originally bound to IPX / SPX, which means that NetWare itself could only use IPX / SPX to communicate over the network. An embedded system based on the Btrieve DBMS was used to store the authentication information.
The first software product named NetWare was released in 1983. It was called NetWare 68 (or Novell S-Net), it ran on a Motorola 68000 processor and used a star topology. This product was superseded in 1985 by NetWare 86, which was written to run on the Intel 8086 processors. Following the release of the Intel 80286 processor, Novell released the NetWare 286 (in 1986). In 1989, with the release of the Intel 80386 processor, NetWare 386 followed. Novell later re-numbered NetWare versions: NetWare 286 became NetWare 2.x, and NetWare became NetWare 3.x.
NetWare 286 2.x
Setting up NetWare version 2 was a significant effort: any change required a kernel recompilation and a system reboot. Recompiling and replacing the kernel required 20 floppy disks in turn. NetWare was administered using text-based tools such as SYSCON. NetWare 2 used the NetWare file system File System 286, or NWFS 286.
NetWare 3.x
NetWare version 3 has been simplified by being modular in design. The functions of the operating system were performed by separate software modules - NetWare Loadable Modules (NLMs) that could be loaded both at system startup and as needed after startup. This architecture made it possible to add the necessary functions to the system, such as anti-virus protection, backup, support for long file names (at that time, file names in common MS-DOS are limited to 8 characters of the name and 3 characters of the extension name) or support for Macintosh files. NetWare management was still offered in text-based utilities. NetWare 3.x introduces a new file system that was used by 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 access rights and security data were stored separately on each server. When there were several servers on the network, users had to register with each of these servers separately, and each server had to contain its own list of users with access rights.
NetWare 4.x
Version 4 introduced Novell Directory Service (NDS) in 1993 — Bindery was replaced by a global directory service that described the entire network infrastructure and was managed from a single point. This meant that the user only had to authenticate to NDS once to access the resources of 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 introduces a number of useful components and utilities such as Novell Distributed Printing Service (NDPS), Java support, and RSA open / closed encryption.
NetWare 4.1x
NetWare 4.11 (intraNetWare) includes a number of improvements to simplify operating system installation and management, as well as make it faster and more stable. Also included with this release was the first full 32-bit client for Microsoft Windows workstations and the NetWare Administrator (NWADMIN or NWADMN32), a graphical NetWare administration utility. At the time, Novell still kept its system tied to the IPX / SPX protocol stack, as NCP was only supported with that stack. However, due to the increasing popularity of TCP / IP, NetWare 4.11 included a number of components and utilities that allowed you to create intranets and connect local networks to the Internet. The operating system provided tools for connecting IPX workstations to IP networks, such as an IPX / IP gateway. Novell for the first time included the Webserver application, which allows you to host Web sites on NetWare servers. This release also began the integration of Internet technologies, for example, through the implementation of the DHCP and DNS protocols on the NetWare platform.
At the same time, Novell has intensified efforts to integrate its products with the NDS directory service. The GroupWise mail system 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 October 1998 release of NetWare 5, Novell recognized the critical role of the Internet and made NCP's core TCP / IP stack support rather than IPX / SPX. The IPX / SPX protocol stack was supported, but TCP / IP became the main stack. Most of Novell's and third-party utilities had to be rewritten to work with TCP / IP, not IPX / SPX. NetWare 5 shipped the first version of the Java graphical administration console, ConsoleOne, which was intended to be used with the NWAdmin utilities.
NetWare 5 was released at a time when NetWare's market share (in Western markets) was declining as NetWare servers were replaced by Windows NT servers. The latest update for the NetWare 4 operating system, NetWare 4.2, has also been released.
Latest version NetWare 5 is now version 5.1. NetWare 5.x included many new features including SAN and cluster support, new NSS (Novell Storage Services) file system replacing the traditional NWFS file system, certificate service, IBM WebSphere, media services, web search services, Oracle 8, Novell SQL, Public Key Infrastructure Service (PKIS) and others.
NetWare 6.x
With the October 2001 release of NetWare 6, the changes were 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 in a specified local iFolder folder with an iFolder server for the subsequent provision of secure universal access to these files on the local network and over the Internet), iManager (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 clients) similar 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 to iFolder servers), and the default web server has been 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
After NetWare 6.5, Novell released the Open Enterprise Server (OES) operating system in 2003, in which users can choose between NetWare and Linux operating system kernel. This integration was completed shortly after Novell acquired Ximian and German GNU / Linux vendor SuSE. Novell is believed to be shifting its focus away from NetWare and porting applications to GNU / Linux. However, Novell officially denies this and says 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-1980s to the late 1990s thanks to its extremely high performance compared to other network operating systems. Most benchmarking tests at the time indicated a performance advantage of between 5: 1 and 10: 1 over Microsoft, Banyan, and others. One benchmark test was particularly interesting: A NetWare 3.x system with NFS over TCP / IP (not the proprietary IPX protocol for NetWare) was compared to an expensive dedicated Auspex NFS server and an SCO Unix server running NFS. NetWare NFS outperformed both NFS systems that are part of their respective operating systems, and 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 LAN datastores were based on the disk server model. This meant that the client computer had to execute the following requests over the relatively slow LAN to read the file block.
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, which is based on the file services model, client interactions occurred at the file API level.
1. Send a request to open a file (if this file has not been opened yet).
2. Send a request for the required data in this file.
All operations to find the directory to determine the location where the required data is physically located on the disk were performed at high speed locally on the server.
By the mid-1980s, most network operating systems were using the file services model instead of the disk services model. Now there is a return to the model of disk services, for example in SAN.
Effectiveness of the NCP protocol
Most of the network protocols used during the development of NetWare did not consider reliable message delivery on the network. Typically, the client read the file as follows.
2. The server acknowledged the receipt of the request.
3. The client acknowledged receipt of the confirmation.
4. The server sent the requested data to the client.
5. The client confirmed the receipt of the data.
6. The server acknowledged receipt of the confirmation.
At the heart of the NCP protocol was the concept of reliable network delivery of packets in most cases. Therefore, the answer to the inquiry served as confirmation in most cases. 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 sequential number, so if the client did not receive a response within the specified time, he would resend the request with the same sequential number. If the server had already processed this request, it would resend the cached response. If the server did not have time to process the request, it would send a "positive acknowledgment".
This “reliable network” model resulted in a two-thirds reduction in network traffic and associated latency.
An operating system without preemptive multitasking designed for network services
In the 90s, the performance of network file services operations by special software in a conventional operating system was intensively compared with the performance of the same operations by a specialized operating system. NetWare was a specialized operating system, not a timesharing operating system. It was written entirely to handle client / server requests. The system was originally focused on file and print services, but later demonstrated excellent legacy capabilities as a platform for databases, email systems, web services, and other services. It also worked effectively as a router for IPX, TCP / IP, and AppleTalk, although it never claimed the flexibility inherent in hardware routers.
NetWare 4.x and earlier did not support preemptive multitasking, timesharing, virtual memory, GUI, and more. The processes and services running in NetWare had to work correctly: process the request and return control to the operating system in the allotted time. In contrast to NetWare, general-purpose operating systems (UNIX, Microsoft Windows) were based on an interactive model with support for a time-sharing mode, when, without control from the operating system, a program could take up all available system resources. These preemptive memory virtualization environments have significant overhead because they never have enough resources to fulfill all the requests of all applications. Such systems have improved over time by tighter integration of network services with the kernel of the "general purpose" operating system, but have never been able to achieve the efficiency level of NetWare. Unfortunately, in the past, when application processes were in control of themselves, this "trust" often led to system crashes.
Perhaps the main reason for Novell's success in the 1980s and 1990s was NetWare's superior performance over general-purpose operating systems. However, as the power of microprocessors increased, the importance 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 benefits of NetWare. The overconfidence of the marketing division and management of Novell against the background of the real threat of competitors (NT4 and Microsoft Exchange) was the last straw in the process, which ultimately led to the loss of NetWare.
Conclusion
As you know, the process of penetration 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 more and more embedded computing facilities. There are more and more users of all this diverse technology, and therefore computers and information systems are becoming more friendly and understandable even for a person who is not a specialist in the field of computer science and computing. This 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, science. A huge role in the process of computerization of the world, in my opinion, 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 in the file system startup process. The item is available to the supervisor or equivalent. NetWare's "accounting system" has a very flexible system of accounting for public resources. Using this menu item, you can view, as well as having certain rights to set up a fee for use ...
Copying files, launching programs, changing directories, and applying extended OS / 2 attributes to files. Write Allows you to write a file. The LAN Manager and LAN Server network operating systems under consideration provide the ability to control access to the keyboard and file server screen. In a special non-dedicated mode of operation, the file server allows users to ...
They work as a single network. Gateways also connect local networks to mainframes - versatile powerful computers. 4. OPERATING SYSTEMS OF LOCAL NETWORKS The emergence of computer networks led to the development of operating systems for personal computers that allow working in networks. Such operating systems provide more than just hardware sharing ...
The network operating system Novell NetWare was once the world market leader. Once upon a time, it was based on the most progressive ideas. However, in the IT industry, everything quickly becomes obsolete, and competitors never sleep.
Microsoft Windows NT is a younger operating system than NetWare. Bill Gates Corporation could not miss the market for network operating systems. By entering the struggle later, but with its characteristic scale, Microsoft began to quickly master the market and was able to avoid some of the mistakes of the first movers.
Novell NetWare
Work on the future NetWare OS began at SuperSet Software, a consulting group founded by friends Drew Major, Dale Nybauer, Kyle Powell and Mark Hirst. They used their work, made at Brigham Young University in Provo, Utah, in October 1981.SuperSet Software was founded in 1979 and was engaged in the production of systems running the CP / M operating system. The group was to create a disk-sharing system for CP / M-based networks.
CP / M (Control Program / Monitor or Control Programs for Microcomputers) is an operating system originally designed for 8-bit microcomputers. Written in 1973 by programmer Gary Kildall in the programming language PL / M (Programming Language for Microcomputers).In the course of its work, the group concluded that the future prospects for CP / M are zero. The team decided to develop their operating system for IBM-compatible PCs, which had just appeared and were "on the crest of the wave." The result was a network operating system that was later named Novell NetWare.
In 1983, Raymond Noorda joined the SuperSet group and became the head of the young company Novell Inc.
In the same year, the company released its first commercial product, NetWare 68 (or Novell S-Net). It was powered by a Motorola 68000 processor. In 1985, NetWare 86 was released, which supported the Intel 8086 processors.
In 1986, after the release of the Intel 80286 processor, Novell released NetWare 286. And in 1989, Intel 80386 and NetWare 386 appeared. Later, Novell decided to give its systems simpler version numbers: for example, NetWare 286 became NetWare 2.x and NetWare 386 is NetWare 3.x.
Reasons for NetWare Success
NetWare used NCP (NetWare Core Protocol) to transfer packets. It was developed on the basis of the previously popular IPX / SPX (Internetwork Packet eXchange / Sequenced Packet eXchange) protocols, developed by the same Novell.NCP was used to organize the exchange between a workstation and a file server. The IPX protocol provided the network layer (packet delivery, analogue of IP), SPX - the transport and session layer (analogue of TCP). True, in the fifth version of NetWare, the manufacturing company still made support for TCP / IP, and not IPX / SPX, as the main for the NCP protocol.
NetWare peaked in popularity in the 1980s and 1990s. It was a convenient system for those times, and very stable: servers running NetWare could work for years without administrator intervention.
Also important was the fact that most benchmarks at the time indicated a performance advantage of between 5: 1 and 10: 1 over Microsoft and other products. This effect was achieved through the use of file service instead of disk services, the efficiency of the NCP protocol, and the absence of preemptive multitasking.In 1993, counting on quick success, Novell released NetWare 4.0 and NDS (then called the NetWare Directory Service), but they were not welcomed with open arms. The new products represented a new approach to networked computing in the enterprise and were very different from anything NetWare 3.x users are used to. Therefore, the most popular version for a long time remained exactly 3.x.
Later, however, the directory service (NDS) included with NetWare 4.x became the industry standard in the corporate environment.
Windows NT
The strongest competitor to Novell NetWare was the Microsoft Windows NT network operating system.It all started in 1975. It was when Digital Equipment Corporation began developing its 32-bit VAX platform, which was later taken over by Microsoft.
In 1977, the VAX-11/780 machine and the operating system for it, VMS 1.0, were announced. The system was developed by David Cutler. Four years later, he decided to leave Digital: he was not satisfied with the pace of development of the project.
Then the management of the company organized an autonomous division in Seattle, and Cutler was allowed to recruit the necessary number of personnel (about 200 people) directly from Digital employees. The new structure took up the design of the processor architecture and operating system, code-named Prism.
However, the managers were unable to bring the business to its logical conclusion, and in 1988 Cutler left the company.
It was then that Bill Gates invited him to Microsoft. By that time, he had just come to the need to create a server operating system that would compete with the Unix clones.
Gates valued David Cutler so much that he agreed to hire 20 former Digital engineers with him. In November 1988, a team of five Digital people and one Microsoft programmer began work on a new operating system. Of course, it was not completely new, since Cutler used his own ideas.
It was necessary to write an OS for the new Intel i860 RISC processor, codenamed N-Ten. From here, by the way, came the abbreviation NT, which was later interpreted by Microsoft marketers as New Technology. Already in December 1988, the first fragments of the system were ready. However, the problem was that the i860 existed only on paper so far, so the code had to be tested on a software emulator. The development was carried out on "toy", by today's standards, Intel 386 25 MHz machines with 13 MB of RAM and 110 MB hard drives.
In 1989 it became clear that the "iron" i860 was not capable of executing the written code efficiently enough. They had to reorient to MIPS R3000, and then to a standard Intel 386 processor, which was done by a team that increased to 28 engineers in a few months.
Development diagram of operating systems of the Windows NT family
In 1990, a key event in the fate of the NT operating system took place - the release and dizzying success of Windows 3.0. In fact, it was Microsoft's first multitasking OS with a decent graphical interface in which you could do real work. It was the borrowing of this interface and API that predetermined the future of NT.
Initially, the server OS was supposed to be a remake of the OS / 2 project jointly with IBM and, accordingly, to function with existing OS / 2 applications.
However, after the release of the third version of Windows, Microsoft abandoned its cooperation with IBM and reoriented the NT development team to design a Win32 API, made in the "image and likeness" of the Win16 interface. This provided the necessary consistency to facilitate porting applications from the desktop to the server platform. So the NT development group, which had turned into Windows NT by that time, grew to almost 300 people.
The refusal to cooperate with IBM led to serious problems in the relationship between the companies. True, there were no official statements, but at one of the intercorporate presentations, IBM employees were surprised to find that the created OS had nothing to do with their OS / 2.
Nevertheless, in Windows NT 3.1 (the numbering was "adjusted" to the current version of 16-bit Windows that existed at that time), support for DOS, Win16, POSIX and OS / 2 API was implemented as well. In July 1993, a new server system from Microsoft was released and began to conquer the market.
Integration
Windows NT 3.5 was released in September 1994. It resolved some of the performance and performance issues that the previous version could not solve due to the haste.However, a new problem appeared: the organization of interaction with networks built on NetWare - the absolute leader at that time, dominating the local network market.
Novell couldn't make the decision to provide Windows NT customer support and was playing for time. As a result, Microsoft was left with a choice: wait another time or write its own client for NetWare.
Gates' company chose the second option and was right: their self-written NetWare client was so good that it continued to be used after the original software from Novell was released. Time was wasted. Moreover, not only it was missed.
Users, especially at first, showed strong dissatisfaction with the positions of Novell and Microsoft. The struggle between network companies provided freedom of choice, but prevented the use of both products in the same environment.
Catch up and overtake
In May 1995, thanks to a microkernel-based architecture, a special "PowerPC-edition" of the operating system, Windows NT 3.51, appeared.PowerPC (or PPC for short) is an RISC microprocessor architecture created in 1991 by an alliance of Apple, IBM and Motorola known as AIM.According to some reports, its release was delayed due to the inability of IBM to adhere to the plan to bring this processor to market. Therefore, the evolution of the PowerPC version went a little further than Windows NT 3.5, which allowed it to become the basis for the next version of the OS.
In Windows NT 4.0, the graphics subsystem was integrated into the kernel. This decision was an absolutely logical conclusion from the sad experience of trying to integrate the popular Windows 95 window environment into NT. Probably, the idea of \u200b\u200brepeating the X Window architecture model - Unix - arose precisely because of the original "server orientation "NT.
However, if in fact there were no problems with the "transplant" of the graphical shell, then its performance in user mode (that is, in the form of a normal application) left much to be desired.
The Windows graphics subsystem is incomparably more complex and, accordingly, more resource-intensive than the X Window, which "understands" only bitmap displays. So, in the kernel of Windows NT 4.0, released in July 1996, there was another module. The revision was named Shell Update Release (SUR).
To turn Windows 95 and Windows NT into universal network clients for any server, Microsoft last year built TCP / IP into its operating systems.
The move to TCP / IP has put significant pressure on traditional network OS vendors using their own protocols. It didn't go unnoticed for Novell either. The company has released a new product, NetWare / IP, a downloadable module that enables IP to be used as a network protocol on a NetWare server. However, this did not help to maintain market leadership.
“NetWare / IP, which initially attracted interest, did not live up to expectations,” said John Miller, network planner at the Apollo Travel Division at United Airlines. "It can't handle the role of a network protocol for servers."
According to Miller, the IPX header requirements meant that Novell did not really support IP or offered any benefit in using it.
The TCP / IP implementation in Netware 5.x did not save the day, as precious time was again lost.
Votes advantage
Large companies, which Microsoft paid direct attention to, did not follow the lead of the corporation and preferred NetWare. However, a survey by Computer Intelligence and InfoCorp found NT to be popular in smaller centers with fewer than 1,000 employees.
Small companies prefer Windows NT (number of companies using NT,%)
However, NT has infiltrated NetWare territory. All decided by the application The choice of one of these systems was highly dependent on which applications the client was using. With time microsoft applications were found on more than half of the NetWare stations reviewed.
Number of NetWare stations using Windows NT,%
As processors increased in power, efficiency became less and less important, and with the introduction of the Pentium processor, the complexity of managing and developing applications for NetWare began to outweigh the benefits. But these facts were stubbornly ignored by the marketing department of Novell, as well as by the company's management.
So Novell NetWare lost its leading position, losing its position to Windows NT.
NetWare OS concept.
NetWare is a network operating system and a set of network protocols that are used in this system to communicate with client computers connected to the network. NetWare is a proprietary operating system that uses cooperative multitasking to run a variety of services on Intel x86-based computers. NetWare was based on a very simple idea: one or more dedicated servers connect to the network and share their disk space in the form of "volumes". MS-DOS client computers run several special TSR programs that allow you to "assign" drive letters to volumes. Users need to log on to the network to access volumes and be able to assign drive letters. Access to network resources is determined by the registration name. The network protocols of the system are based on the Xerox XNS protocol stack.
Xerox Network Systems (XNS) protocols were developed by Xerox Corporation in the late 1970s and early 1980s. They are designed for use in a wide variety of transmission media, processors, and office applications. Several XNS protocols are similar to the Internet Protocol (IP) and Transmission Control Protocol (TCP), developed by DARPA for the US Department of Defense (DoD). Since its inception, each company has made various changes to the XNS protocols. Novell has supplemented them with the Service Access Protocol ( Service access protocol - SAP) to provide advertisements of resources, and modified OSI Layer 3 protocols (which Novell renamed to Internetwork Packet Exchange - IPX - Exchange of internetwork packets) for operation in IEEE 802.3 networks, and not in Ethernet networks.
NetWare currently supports TCP / IP and IPX / SPX.
IPX is designed to transmit datagrams in connectionless systems (like IP or NETBIOS, developed by IBM and emulated at Novell), and allows communication between NetWare servers and endpoints. The maximum size of an IPX datagram is 576 bytes, of which 30 bytes is occupied by the header. It is assumed that the network through which these datagrams are transported is capable of forwarding packets of the appropriate length.
SPX (Sequence Packet eXchange) and its enhanced version SPX II are transport protocols of the 7-layer ISO model. This protocol guarantees packet delivery and uses a sliding window technique (a distant analogue of TCP). In case of loss or error, the packet is re-sent, the number of repetitions is set programmatically. SPX does not support broadcast or multicast addressing. The SPX indicates a situation when a partner unexpectedly terminates the connection, for example, due to a disconnection. SPX packets are embedded in IPX packets.
Despite the fact that in earlier versions of NetWare all modules of the system were considered unreliable (any module malfunctioning could disrupt the entire system), it was a very stable system. It is not uncommon for NetWare servers to run without human intervention for years.
This network operating system was later named Novell NetWare. NetWare uses the protocol NCP (from english NetWare Core Protocol, which is a packet transfer protocol that allows clients to send requests to and receive responses from NetWare servers. NCP is the language of communication between servers and clients in the NetWare environment. NCP was originally bound to protocols IPX / SPXthat is, NetWare itself could only use IPX / SPX to communicate over the network.
Novell Protocols
The Novell NetWare protocol stack is influenced by the XNS (Xerox Network System) architecture. Novell protocols provide support for most current desktop operating systems, including DOS, Windows, Macintosh, OS / 2, and UNIX. In addition, Novell provides efficient LAN and WAN support based on asynchronous connections. The Novell stack includes the following protocols:
IPX (Internetwork Packet Exchange) was developed by Novell based on the Internet Datagram Protocol (IPX) from Xerox. IPX is a connectionless protocol that delivers packets over the Internet and supports addressing and routing of NetWare workstations and servers.
The Broadcast protocol (BCAST) notifies users that messages have been received for them over the network.
BMP (Burst Mode Protocol) actually uses NCP packets (request type 7777H). BMP provides support for multiple responses to a single file read or write request. Batch mode improves the efficiency of communication between the server and clients, allowing workstations to receive (transmit) from the server up to 64 KB of data on a single read or write request. When describing the BMP protocol, we will use the Russian term "group" for the term burst (burst, packet) in order to avoid confusion with the term "packet".
The Diagnostic Responder (DIAG) is a convenient tool for analyzing NetWare LANs. DIAG protocol can be used to test connections, verify configuration, or gather information.
NetWare Core Protocol (NCP) is used to control access to core resources on a NetWare server. NCP calls NetWare File Sharing Protocol (NFSP) routines to gain access to resources. The NFSP protocol handles requests for NetWare file and printer resources.
NDS (NetWare Directory Service) is a globally distributed network database that replaces the bindery used in earlier versions of NetWare. In a network that supports NDS, you only need to register on the network once to gain access to all network resources (no registration is required on each server).
NLSP 1 "1 (NetWare Link Service Protocol) is a link state routing protocol for IPX networks. This protocol provides the required information exchange between routers in large IPX networks. IPX is used at the Novell network layer. NetWare.
This protocol was developed by Novell based on the NetBIOS protocol.
In NovelNetBIOS protocol packets, the data stream type field has a fixed size (1 byte), and the rest of the fields have a variable length.
Routing Information Protocol (RIPX) is used to collect, maintain, and exchange correct routing information between gateways on the Internet. The protocol described here should be distinguished from RIP in the TCP / IP stack.
To ensure correct licensing of server software on the NetWare network, each server broadcasts special packets (Serialization). These packages contain the serial number of the server software and allow you to record the presence of two or more copies of the same software package on the network.
Verification packets contain only one 6-byte data field.
Before a client station can establish a connection to a server, it must learn about the servers available on the network. The SAP (Service Advertising Protocol) protocol is used to provide the stations with the required information. The SAP protocol distributes information about all servers present in the enterprise network. These servers can be file servers, print and access servers, and other types of servers.
The SPX (Sequenced Packet Exchange) protocol was developed by Novell based on the SPP (Sequenced Packet Protocol) from Xerox. The protocol operates at the transport layer and provides packet delivery for higher layer applications.
In July 1991, Novell began development of the next version of the SPX protocol, SPX II. The main improvements in SPX II over SPX are support for larger packet sizes and the ability to use windowed protocols.
Watchdog (Watchdog) protocol continuously monitors connections on active workstations and notifies the NetWare operating system if a connection might be closed due to prolonged inactivity.
Services for Novell NetWare
Windows 2000 provides services that allow Windows computers to coexist and coexist with Novell NetWare-based networks and servers. Some of these services are included in Windows 2000 Server and Windows 2000 Professional, others are available as separate products: NWLink IPX / SPX / NetBIOS Compatible Transport Protocol (NWLink IPX / SPX / NetBIOS Compatible Transport Protocol) included with Windows 2000 Server and Windows 2000 Professional and is the implementation of IPX / SPX in Windows 2000. NWLink supports interoperability between Windows computers and NetWare computers, and other compatible systems. NWLink can also be used as a protocol connecting multiple computers running Windows NT, Windows 2000, Windows for Workgroups, Windows 95/98 with the Microsoft network client software for MS-DOS computers installed.
Gateway Services for NetWare (GSNW) is included with Windows 2000 Server and allows a Windows 2000-based computer to connect to NetWare servers from version 4.dg and higher running either Novell Directory Service ( NDS), or the Bindery service database. Also included is network logon script support. In addition, you can use GSNW to create gateways to NetWare resources. Creating gateways allows computers running only Microsoft client software to access NetWare resources.
Client Services for NetWare (CSNW) is included with Windows 2000 Professional and allows client computers to establish direct connections to file shares and printers on servers running NetWare 2.x and later. CSNW supports NetWare 4.x or higher servers that run either Bindery or NDS. CSNW also includes support for network logon script.
Directory Synchronization Services (MSDSS) is included with Services for NetWare v. 5 (see Chapter 24) and provide the ability to migrate user and group accounts from NetWare servers to Active Directory. The NetWare server you are migrating from can use NDS or Bindery like NetWare 3.x.
The Microsoft File Migration Utility (MSFMU) is included with Services for NetWare v. 5 and is designed to bring NetWare Shares to Windows 2000.
File and Print Services for NetWare (FPNW) is a separate product. FPNW Services enables a Windows 2000 Server-based computer to provide print and file services directly to and compatible with NetWare clients. NetWare clients see this kind of server like any other NetWare server and can access its volumes, files, and printers. No changes to the NetWare client software are required.
The network operating system Novell NetWare was once the world market leader. Once upon a time, it was based on the most progressive ideas. However, in the IT industry, everything quickly becomes obsolete, and competitors never sleep.
Microsoft Windows NT is a younger operating system than NetWare. Bill Gates Corporation could not miss the market for network operating systems. By entering the struggle later, but with its characteristic scale, Microsoft began to quickly master the market and was able to avoid some of the mistakes of the first movers.
Novell NetWare
Work on the future NetWare OS began at SuperSet Software, a consulting group founded by friends Drew Major, Dale Nybauer, Kyle Powell and Mark Hirst. They used their work, made at Brigham Young University in Provo, Utah, in October 1981.SuperSet Software was founded in 1979 and was engaged in the production of systems running the CP / M operating system. The group was to create a disk-sharing system for CP / M-based networks.
CP / M (Control Program / Monitor or Control Programs for Microcomputers) is an operating system originally designed for 8-bit microcomputers. Written in 1973 by programmer Gary Kildall in the programming language PL / M (Programming Language for Microcomputers).In the course of its work, the group concluded that the future prospects for CP / M are zero. The team decided to develop their operating system for IBM-compatible PCs, which had just appeared and were "on the crest of the wave." The result was a network operating system that was later named Novell NetWare.
In 1983, Raymond Noorda joined the SuperSet group and became the head of the young company Novell Inc.
In the same year, the company released its first commercial product, NetWare 68 (or Novell S-Net). It was powered by a Motorola 68000 processor. In 1985, NetWare 86 was released, which supported the Intel 8086 processors.
In 1986, after the release of the Intel 80286 processor, Novell released NetWare 286. And in 1989, Intel 80386 and NetWare 386 appeared. Later, Novell decided to give its systems simpler version numbers: for example, NetWare 286 became NetWare 2.x and NetWare 386 is NetWare 3.x.
Reasons for NetWare Success
NetWare used NCP (NetWare Core Protocol) to transfer packets. It was developed on the basis of the previously popular IPX / SPX (Internetwork Packet eXchange / Sequenced Packet eXchange) protocols, developed by the same Novell.NCP was used to organize the exchange between a workstation and a file server. The IPX protocol provided the network layer (packet delivery, analogue of IP), SPX - the transport and session layer (analogue of TCP). True, in the fifth version of NetWare, the manufacturing company still made support for TCP / IP, and not IPX / SPX, as the main for the NCP protocol.
NetWare peaked in popularity in the 1980s and 1990s. It was a convenient system for those times, and very stable: servers running NetWare could work for years without administrator intervention.
Also important was the fact that most benchmarks at the time indicated a performance advantage of between 5: 1 and 10: 1 over Microsoft and other products. This effect was achieved through the use of file service instead of disk services, the efficiency of the NCP protocol, and the absence of preemptive multitasking.In 1993, counting on quick success, Novell released NetWare 4.0 and NDS (then called the NetWare Directory Service), but they were not welcomed with open arms. The new products represented a new approach to networked computing in the enterprise and were very different from anything NetWare 3.x users are used to. Therefore, the most popular version for a long time remained exactly 3.x.
Later, however, the directory service (NDS) included with NetWare 4.x became the industry standard in the corporate environment.
Windows NT
The strongest competitor to Novell NetWare was the Microsoft Windows NT network operating system.It all started in 1975. It was when Digital Equipment Corporation began developing its 32-bit VAX platform, which was later taken over by Microsoft.
In 1977, the VAX-11/780 machine and the operating system for it, VMS 1.0, were announced. The system was developed by David Cutler. Four years later, he decided to leave Digital: he was not satisfied with the pace of development of the project.
Then the management of the company organized an autonomous division in Seattle, and Cutler was allowed to recruit the necessary number of personnel (about 200 people) directly from Digital employees. The new structure took up the design of the processor architecture and operating system, code-named Prism.
However, the managers were unable to bring the business to its logical conclusion, and in 1988 Cutler left the company.
It was then that Bill Gates invited him to Microsoft. By that time, he had just come to the need to create a server operating system that would compete with the Unix clones.
Gates valued David Cutler so much that he agreed to hire 20 former Digital engineers with him. In November 1988, a team of five Digital people and one Microsoft programmer began work on a new operating system. Of course, it was not completely new, since Cutler used his own ideas.
It was necessary to write an OS for the new Intel i860 RISC processor, codenamed N-Ten. From here, by the way, came the abbreviation NT, which was later interpreted by Microsoft marketers as New Technology. Already in December 1988, the first fragments of the system were ready. However, the problem was that the i860 existed only on paper so far, so the code had to be tested on a software emulator. The development was carried out on "toy", by today's standards, Intel 386 25 MHz machines with 13 MB of RAM and 110 MB hard drives.
In 1989 it became clear that the "iron" i860 was not capable of executing the written code efficiently enough. They had to reorient to MIPS R3000, and then to a standard Intel 386 processor, which was done by a team that increased to 28 engineers in a few months.
Development diagram of operating systems of the Windows NT family
In 1990, a key event in the fate of the NT operating system took place - the release and dizzying success of Windows 3.0. In fact, it was Microsoft's first multitasking OS with a decent graphical interface in which you could do real work. It was the borrowing of this interface and API that predetermined the future of NT.
Initially, the server OS was supposed to be a remake of the OS / 2 project jointly with IBM and, accordingly, to function with existing OS / 2 applications.
However, after the release of the third version of Windows, Microsoft abandoned its cooperation with IBM and reoriented the NT development team to design a Win32 API, made in the "image and likeness" of the Win16 interface. This provided the necessary consistency to facilitate porting applications from the desktop to the server platform. So the NT development group, which had turned into Windows NT by that time, grew to almost 300 people.
The refusal to cooperate with IBM led to serious problems in the relationship between the companies. True, there were no official statements, but at one of the intercorporate presentations, IBM employees were surprised to find that the created OS had nothing to do with their OS / 2.
Nevertheless, in Windows NT 3.1 (the numbering was "adjusted" to the current version of 16-bit Windows that existed at that time), support for DOS, Win16, POSIX and OS / 2 API was implemented as well. In July 1993, a new server system from Microsoft was released and began to conquer the market.
Integration
Windows NT 3.5 was released in September 1994. It resolved some of the performance and performance issues that the previous version could not solve due to the haste.However, a new problem appeared: the organization of interaction with networks built on NetWare - the absolute leader at that time, dominating the local network market.
Novell couldn't make the decision to provide Windows NT customer support and was playing for time. As a result, Microsoft was left with a choice: wait another time or write its own client for NetWare.
Gates' company chose the second option and was right: their self-written NetWare client was so good that it continued to be used after the original software from Novell was released. Time was wasted. Moreover, not only it was missed.
Users, especially at first, showed strong dissatisfaction with the positions of Novell and Microsoft. The struggle between network companies provided freedom of choice, but prevented the use of both products in the same environment.
Catch up and overtake
In May 1995, thanks to a microkernel-based architecture, a special "PowerPC-edition" of the operating system, Windows NT 3.51, appeared.PowerPC (or PPC for short) is an RISC microprocessor architecture created in 1991 by an alliance of Apple, IBM and Motorola known as AIM.According to some reports, its release was delayed due to the inability of IBM to adhere to the plan to bring this processor to market. Therefore, the evolution of the PowerPC version went a little further than Windows NT 3.5, which allowed it to become the basis for the next version of the OS.
In Windows NT 4.0, the graphics subsystem was integrated into the kernel. This decision was an absolutely logical conclusion from the sad experience of trying to integrate the popular Windows 95 window environment into NT. Probably, the idea of \u200b\u200brepeating the X Window architecture model - Unix - arose precisely because of the original "server orientation "NT.
However, if in fact there were no problems with the "transplant" of the graphical shell, then its performance in user mode (that is, in the form of a normal application) left much to be desired.
The Windows graphics subsystem is incomparably more complex and, accordingly, more resource-intensive than the X Window, which "understands" only bitmap displays. So, in the kernel of Windows NT 4.0, released in July 1996, there was another module. The revision was named Shell Update Release (SUR).
To turn Windows 95 and Windows NT into universal network clients for any server, Microsoft last year built TCP / IP into its operating systems.
The move to TCP / IP has put significant pressure on traditional network OS vendors using their own protocols. It didn't go unnoticed for Novell either. The company has released a new product, NetWare / IP, a downloadable module that enables IP to be used as a network protocol on a NetWare server. However, this did not help to maintain market leadership.
“NetWare / IP, which initially attracted interest, did not live up to expectations,” said John Miller, network planner at the Apollo Travel Division at United Airlines. "It can't handle the role of a network protocol for servers."
According to Miller, the IPX header requirements meant that Novell did not really support IP or offered any benefit in using it.
The TCP / IP implementation in Netware 5.x did not save the day, as precious time was again lost.
Votes advantage
Large companies, which Microsoft paid direct attention to, did not follow the lead of the corporation and preferred NetWare. However, a survey by Computer Intelligence and InfoCorp found NT to be popular in smaller centers with fewer than 1,000 employees.
Small companies prefer Windows NT (number of companies using NT,%)
However, NT made its way into NetWare territory. Everything was decided by the application. The choice of one of these systems was highly dependent on which applications the client was using. Over time, Microsoft applications ended up on more than half of the NetWare stations reviewed.
Number of NetWare stations using Windows NT,%
As processors increased in power, efficiency became less and less important, and with the introduction of the Pentium processor, the complexity of managing and developing applications for NetWare began to outweigh the benefits. But these facts were stubbornly ignored by the marketing department of Novell, as well as by the company's management.
So Novell NetWare lost its leading position, losing its position to Windows NT.
