Novell Network | Part 2

Novell Network | Part 2

NetWare 3.x

Starting with NetWare 3.x, was added to 32-bit protected mode, which allowed the operating system to eliminate the limit of 16mb memory NetWare 2.x This paved the way to support larger hard disk, since NetWare 3.x held in cache (copied) in full for the RAM File Allocation Table (FAT) and directory entry table (DET), resulting in improved performance.

NetWare version 3 eased development and administration by modularization. Each functionality was controlled by a software module called NetWare Loadable Module (NLM), or loaded at startup or when needed. Became possible to add features like anti-virus software, backup software, database and web servers, support for extended file names (file names were limited to standard eight characters plus a three-letter extension, such as MS-DOS) or Macintosh style files.

Continue to be administered using NetWare utilities in text mode. The file system introduced by using the default Netware 3.x to Netware 5.x was NetWare File System 386, or 386 NWFS, which significantly expanded the capacity of volumes (1 TB, with up to 4 GB files) and could handle volume up to 16 segments that could span multiple physical disks. The volume segments could be added while the server was in use and the volume mounted, allowing the server to be expanded without interruption.

The NetWare Bindery services were initially used for authentication. It was a stand-alone database system, in which all data access and security of people residing on each server. When a facility contains more than one server, users had to authenticate to each individually, and each server must be configured with a list of all authorized users.

“NetWare Name Services” was a product that extends the user’s data across multiple servers, and the concept of “domain” used by Windows is functionally equivalent to NetWare v3.x Bindery services with the addition of NetWare Name Services (or a two-dimensional database, with a flat namespace and a static scheme).

For a short time Novell also marketed an OEM version of NetWare 3, called Portable NetWare, along with manufacturers such as Hewlett-Packard, DEC and Data General, which led to the source code for NetWare to run on their Unix operating systems. Portable NetWare had only marginal success.

In the era 3.x, Novell introduced its first high-availability clustering system, named NetWare SFT-III, which allowed a logical server to be “mirrored” on a completely separate physical machine. Implemented as a shared-nothing cluster, SFT-III with the operating system was logically divided into an I / O interrupt-driven engine and a generic event-driven system. The I / O engine serialize their interrupts (disk, network, etc.) In a combined flow of events that was fed to two identical copies of the engine system, through a fast link (typically 100 Mbit / s) between the two server. Because of its non-preemptive, the core operating system, stripped of the I / O is not deterministic, deterministically behaving like a big finite state machine.

The output of the two engine system was compared to ensure proper operation, and two copies were sent back to the I / O engine. Using the existing functionality of SFT-II software RAID in the kernel, the disks could be mirrored between the two machines without using special hardware. The two machines could be separated up to the maximum allowed by the linked server. In case of failure to a server or a disk, the server could survive, after a brief pause, take over client sessions transparently, since it had all the status information and should not, for example, replace the volumes ( a process in which NetWare was notoriously slow). Incidentally, SFT-III was the first version of NetWare in a position to make use of SMP hardware (I / O engine could optionally be run on a dedicated CPU).

NetWare SFT-III, being ahead of its time in many ways, was a partial success. It should also be noted that the modern incarnation of NetWare’s clustering, called Novell Cluster Services (introduced with NetWare 5.0), is very different from SFT-III.

NetWare 3.x was designed to run all the applications on servers at the same level of memory protection, known as “ring 0”. This gave the best performance possible, but sacrificing reliability. The result was the possibility of system outages, (known as Abend, contraction of Abnormal End, abnormal end). From NetWare 5.x, software modules (NetWare Loadable Modules or NLM) could be allocated to the performance in different rings (rings) security processor, thus ensuring that a software error is not blocking the system.

In comparison, even up to Windows NT v4.0, many “recommended practices” included monthly or even weekly reboot of Windows servers to overcome the loss of memory.

NetWare 4.x

Version 4, released in 1993, introduced the Novell Directory Services (NDS), based on the X.500 protocol, which replaced the bindery services with a global directory service, where the infrastructure was described and managed in one place. In addition, NDS provides an extensible framework, allowing the addition of new types of objects. This allowed a single user authentication to NDS that governed access to any server in the directory tree. Users could then access the network resources, regardless of the server where it lies, even if the user license count was still tied to individual servers (the large companies could opt for a licensing model, which essentially allows an unlimited number of users for if allowed to Novell server to verify the total number of users)

Version 4 also introduced several features and tools, such as transparent compression of files on the file system level encryption and RSA public / private.

At this point, however, the strategic mistakes became clear.

Strategic errors

The strategy of Novell NetWare 2.x and 3.x had been very successful. Before the arrival of Windows NT 3.5, Novell held 90% of the market for servers based on PC architecture. The assumption by Novell was to extend this domain by adding the directory services in NetWare 4.x NDS The crucial error was to make NDS a requirement and not an option. If NDS was an option for NetWare 4, or even a product purchased separately, many people would continue to use NetWare instead of switching to Windows NT. This was especially true for smaller networks, where the NDS, as conceptually they were far more advanced than Bindery services or Windows domains, will require some initial effort of training IT staff.

While the design of NetWare 3.x and later provided a DOS partition to load the NetWare file system, this feature became a constraint, since new users preferred the Windows graphical user interface to have to learn DOS commands to build a NetWare server. Novell could remove this constraint while maintaining the technical design of NetWare 2.x, which installs the system files on a NetWare partition and allowed the server to boot from this, without having to create a bootable DOS partition. Novell finally added support for this mode in a Support Pack for NetWare 6.5.

Given that Novell used IPX / SPX instead of TCP / IP, was poorly positioned to take advantage of the Internet in 1995. The first implementation of TCP / IP for NetWare 3.x, was not fully compatible with IPv4. This meant that the overrun on the NetWare server, for routing and access to the Internet, the router hardware (like Cisco) and Linux servers for the functionality of web servers.

NetWare 4.02, 4.1x NetWare for Small Business: Novell begins to recover

Novell NetWare 4.2 released shortly after the release of NetWare 4.01, by introducing a simple installation of the NDS. In 1996, Novell released version 4.11, which included many enhancements that make the operating system easier to install, easier to operate, faster and more stable.

This version also included the first fully 32-bit client for Microsoft Windows-based workstations, SMP support and NetWare Administrator (or NWADMIN NWADMN32), a graphical administration tool for NetWare.

Novell NetWare 4.11 fashioned with its Web server, supporting TCP / IP and the Netscape browser, in a bundle called IntranetWare. A version designed for networks with up to 25 people were baptized IntranetWare for Small Business and happy a limited version of the NDS and tools for simplified administration. IntranetWare was abandoned with NetWare 5.

During this time Novell also realized the importance of building on the directory service, NDS, linking to them even its other products. The e-mail system, GroupWise, was integrated with NDS, and Novell released many other products “directory-enabled” as ZENworks and BorderManager.

At that point it was still tied to Novell IPX / SPX protocol dependence on PCN at that, but Novell began to recognize the request for the TCP / IP with NetWare 4.11, adding tools and utilities that make it easier to create intranets and networks connecting to the Internet. Novell attachments practical tools, such as Gateway IPX / IP, were used to facilitate the connection between IPX workstations and IP networks. He also began to incorporate Internet technologies and their support through features such as a native Web server.