Datasheet
12
CHAPTER 1
WINDOWS SERVER 2008 ARCHITECTURE
memory as a dynamic pool. The Memory Manager in Windows Server 2008 was rewritten to allow
better handling of the allocation of virtual addresses, kernel page tables, and for the support for
very large Registries, all features that make NUMA more robust.
If you’ve been running Vista, you know that the video subsystem was substantially upgraded
from previous Windows versions. Part of the new graphics subsystem in Windows Server 2008 and
Vista offloads more graphics routines from the CPU onto the video card’s graphics processing unit
(GPU), which calls for considerably more video memory. The Aero Glass interface requires a min-
imum of 256MB of video RAM. Simply maintaining the Windows+Alt CoolSwitch, Flip, or Task
Switcher application requires something on the order of 56MB of video RAM.
Terminal Server received a big enhancement in Windows Server 2008, and that is the subject
of Chapter 12. The main operational difference from a user prospective is the Terminal Services
RemoteApp feature. A RemoteApp is a program that you can run in a Terminal Server session that
behaves as if it was running locally on the user’s computer. RemoteApp removes the problems
users had with managing Terminal Server sessions and moving between the local desktop and the
remote desktop. When two or more RemoteApps run, they can do so within the same Terminal
Server session. To support RemoteApps the Memory Manager introduces a new type of memory
construct called Terminal Services session objects. RemoteApps makes the experience of using the
virtual desktop of Terminal Server equivalent (also known as transparent) in terms of user experi-
ence to local applications, something that will make it much easier for users to learn and use.
The New Boot Environment
Microsoft has created a completely new boot environment for Windows Vista and Windows Server
2008 that greatly improves the installation of the operating system, handling of backups and restores
from images, and direct system startup into a mini-OS that is capable of network installations, sys-
tem diagnostics, and repairs. The most important part of this new feature is the Boot Configuration
Data (BCD) store. BCD is Windows Server 2008 itself, albeit a stripped-down version of Windows.
The BCD can boot from the PC BIOS or from the newer Extensible Firmware Interface (EFI). EFI
is the renamed version of the Intel Boot Initiative, which is now supported by an industry group
called the Unified Extensible Firmware Interface (UEFI) Forum (
http://www.uefi.org
). EFI is a
software interface between the operating system and your computer’s firmware that maintains a
current table of platform information; boot services such as console, bus, and file system services;
and runtime services such as Date/Time and the information contained in nonvolatile RAM. One
of the nicest features of EFI’s boot manager is the ability to abstract device drivers, a bootable shell
(EFI Shell), and an extensible architecture.
NOTE
Sixty-four-bit Windows Server 2008 will not boot from a system with PC BIOS, or by using
an abstraction layer. EFI is a requirement for any Intel Itanium system loading 64-bit Windows
Server; Vista makes no such requirement on 64-bit chips such as AMD Opteron and others.
BCD is available during and after system boot, and while it was meant to support Vista and
Windows Server 2008 it is a great general-purpose boot environment that can support numerous
third-party tools. Indeed, many utilities will appear based on BCD in the future. There is some
backward compatibility to Windows 2003 and XP; BCD will correctly launch
NTLDR.EXE
, which
then draws its configurational data from the
BOOT.INI
file. Since BCD is so central to Microsoft’s
automated Windows deployment system, you’ll find a more complete discussion of the BCD and
deployment in the next chapter.
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