Instructor Note The figure in slide 7, Windows 2000 Architectural Overview (which is also Figure 1.1 on page 8 of the ALS: Microsoft Windows 2000 Server textbook), provides an overview of the Windows 2000 operating system architecture. Like all operating systems, Windows 2000 contains many lines of code that are designed to make computer hardware available to applications. This figure merely provides a conceptual framework for understanding how the code fits together. Therefore, diagrams from different sources may vary from this one.
A. Supports devices and drivers that are hardware-configurable and software-configurable
B. Runs uniformly on uniprocessor and SMP platforms
C. Supports packet-driven I/O with reusable I/O request packets and asynchronous I/O
|8| 2. Architectural Layers
|9| A. User mode
|10| 1. Environment subsystems
a. Allow Windows 2000 to run applications written for different operating systems
b. Emulate different operating systems by presenting the APIs that need to be available for the applications
c. Support for two environment subsystems: Win32 and POSIX
d. Have no direct access to hardware or device drivers
e. Run at a lower priority than kernel-mode processes
Instructor Note Microsoft Enterprise Memory Architecture (EMA), part of Windows 2000 Advanced Server and Windows 2000 Datacenter Server, can make larger amounts of physical RAM available to applications, thereby improving their performance.
|11| 2. Integral subsystems
a. Perform essential operating system functions
b. Include several important integral subsystems
Instructor Note Refer to the table on page 10 for a description of each of the following integral subsystems.
(2) Workstation service
(3) Server service
|12| B. Kernel mode
|13| 1. Windows 2000 Executive
a. Performs most of the I/O and object management
b. Provides system services and internal routines
c. Includes a number of components
Instructor Note Refer to the table on pages 11–12 for a description of each of the following components.
(1) I/O Manager
(2) Security reference monitor
(3) Interprocess Communication (IPC) Manager
(4) Virtual Memory Manager (VMM)
(5) Process Manager
(6) Plug and Play (PnP) Manager
(7) Power Manager
(8) Window Manager and graphical device interface (GDI)
(9) Object Manager
|14| 2. Hardware Abstraction Layer (HAL)
a. Virtualizes the hardware interface details
b. Contains hardware-specific code that handles I/O interfaces, interrupt controllers, and multiprocessor communication mechanisms
Instructor Note Support for Alpha-based hardware was discontinued after Windows 2000 Release Candidate One.
c. Implemented as a dynamic-link library and responsible for all hardware-level, platform-specific support
|15| 3. Kernel Mode Drivers
a. Implemented as discrete, modular components with a well-defined set of required functionality
b. Include a set of system-defined standard driver routines and some internal routines
c. Support three basic types of drivers
Instructor Note Refer to the table on page 15 for a description of each of the following types of kernel-mode drivers.
(1) Highest-level drivers
(2) Intermediate drivers
(3) Lowest-level drivers
|16| d. Windows Driver Model (WDM)
(1) Subset of the intermediate level of kernel-mode drivers
(2) Enables devices designed for Windows 2000 or Windows 98 to be installed and used with computers running under either operating system
(3) Based on a class/miniport structure that provides modular, extensible architectures for device support
|17| e. WDM Layered Architecture
(1) Uses special class drivers to provide cross-platform support
4. A local security database maintained by each computer in the workgroup
5. Changes to accounts made on each computer
6. Provides a number of advantages
a. Does not require a computer running Windows 2000 Server
b. Simple to design and implement
c. Convenient for a limited number of computers in close proximity (no more than 10 computers)
d. Well suited to small groups of technical users who do not require centralized administration
Instructor Note In a workgroup, a computer running Windows 2000 Server is called a stand-alone server.
|21| B. Windows 2000 domains
1. A logical grouping of network computers that share a central directory database
Instructor Note The directory resides on domain controllers. A domain controller is a server that manages all security-related user/domain interactions and centralizes administration. In Windows NT domains, domain controllers are either backup domain controllers (BDCs) or primary domain controllers (PDCs). In Windows 2000 domains, there is only one type of domain controller, and all domain controllers are peers.
2. Not limited to a single location or a specific type of network configuration
3. Can share physical proximity on a small LAN or can be located in different parts of the world