Why Two Products?
When Microsoft introduced Windows NT in 1993, they offered two products: Windows NT 3.1 and Windows NT Advanced Server 3.1. The problem was that the exact roles of these two products had not been clearly defined in Microsoft´s marketing strategy. This led to confusion about which product should be used in what environments.
With the inroduction of 3.5 in late 1994, Microsoft changed the product names, their feature became Windows NT Workstation, and Windows NT Advanced Server became Windows NT Server.
Windows NT Workstation was designed as a robust, 32-bit multithreaded, multitasking operating system that was capable of running high-end engineering or mission-critical client/server applications.
Windows NT Server became the cornerstone of Microsoft´s enterprise-class network operating system. Windows NT Server was designed to provide file, print, and application services to diverse clients.
Features Common to Both Windows NT Server and Windows NT Workstation
Windows NT Workstation and Windows NT Server are both built using the same core technologies, resulting in products with more similarities than differences. Some of the features common to both Windows NT products are
*High-performance client/server platform
*Network foundation
*GUI management tools
*NetWare inegration
*Robust TCP/IP services
*Remote Access Service (RAS)
*Integrated C2-level security
*Build-in backup
*Advanced file systems
Additional Features in Windows NT Server
The features discussed are shared by both the NT Workstation and the NT server products. There are many features available in the NT Server product that are not available in the Workstation product. Some of the most importatns features are
*Increased server capacity for servicing more simultaneous connections
*Fault-tolerant disk driver for supporting disk mirroring and disk striping with parity (RAID 1 and RAID 5)
*Enhanced TCP/IP server services,such as DHCP,WINS,DNS
*Internet Information Server 2.0
*Additional NetWare integration tools
*Unified domain-based security model
*Network client administrator
*Directory replication
*Services for Macintosh
*Remoteboot (RPL) for clients
*Client-licensing manager
*BackOffice suite intergration
*Network Monitor Tool
Increased Server Capacity
Whereas NT Workstation is limited to 10 incoming network connections, Windows NT Server has no such limitation. In fact, there is no software-defined limit to the number of clients that can simultaneously connect to an NT Server. The limit of 10 network connections in NT Workstation is not simply a whimsically chosen number. After careful benchmarking and analysis, Microsoft determined that NT Workstation and NT Server performed similarly up to about 10 simultaneous incoming network connections. After that, NT Server was much more capable of handing the load. This has to do with differences in the internal optimization of the two products, including the pagebility of the server core and the difference in the number of system worker threads.
To design this system, Microsoft hired David Cutler, and operating system designer with Digital Equipment Corporation (DEV), and a group of his coworkers from DEV. David was renowned for his work on DEC operating systems, includeing RSX-11M(which helped turn DEC´s PDP-11 mini-computer into a great world-wide success), and on his work with the VAX architecture.
The internals of Windows NT were written from scratch and centered around a microkernelstyle architecture similar to UNIX. This microkernel gave Windows NT preemtive multitasking. Additionally, Windows NT made use of process thread–an idea popularized by Carnegie Mellon´s MACH operating system–to support symmetric multiprocessing (SMP).
When NT was finally released, Microsoft came to market with two different versions, Windows NT 3.1 and Windows NT Advanced Server 3.1. While these two products represented a tremendous achievement, their lack of compatibility with existing Windows programs and their steep hardware requirement prevented them from making significant in-road in the network operating system environment, which was dominated by Novell´s NetWare product.
Það er ein villa í textanum sem ég sendi fyrir :
“Þeir kölluðu það Windows NT.
Til að losa sig við gamla ”Preemtive multitasking“ úr Windows 3.x þá notuðu þeir UNIX microkernel til að ná sér í ”Multitasking“ eiginleika.”
Það er cooperative multitasking en ekki “Preemtive” (Smá villa í minnisblöðunum).
Þegar ég sagði “UNIX microkernel” átti ég við UNIX Architecture, en ekki einhvern UNIX kernel.