Deploying with Windows DS : Introducing Windows DS - Service Architecture & Operating Modes

Windows DS images are collected from client master systems and stored in single instance storage (SIS) on the server. Clients can be booted from PXEcompliant network adapters or by using remote client boot disks. The Windows DS client boots into a customized Windows PE image, and the user can select the installation image from a list of images stored on the server. Windows DS installations can also be scripted for unattended installation support and to support Lite Touch Installation (LTI) and Zero Touch Installation (ZTI) scenarios.

Service Architecture

The Windows DS architecture has three major categories of components:

• Management components Management components are a set of tools that you use to manage the server, operating system images, and client computer accounts. The Windows DS MMC snap-in is a management component, and the command-line interface is another.

• Service components Server components include a PXE server for network booting a client to load and install an operating system. Server components also include a shared folder and image repository that contains boot images, installation images, and files that you need specifically for network boot.

• Client components Client components include a graphical user interface (GUI) that runs within Windows PE and communicates with the server components to select and install an operating system image.

Figure 1 illustrates the various components of Windows DS. The following sections describe the image store, PXE server, management, and client components in more detail.

Figure 1. Windows DS Architecture.

Image Store

Figure 2 describes how Windows DS organizes the image store.

Organizing images into groups, as shown in Figure 2, provides two benefits. First, image groups allow you to better manage and organize images. For example, you can manage the security of an entire image group, rather than managing the security of individual images. Second, image groups provide units of single instancing. This means that all of the images within an image group use SIS to significantly compress their contents. The file Res.rwm contains all of the file resources for the image group, and this file uses SIS. Each image file (Install.wim and Install2.wim in Figure 2) only contain metadata that describes the image file contents based on the contents of Res.rwm.

Windows DS references images by their group name and image file name. For example, the image ImageGroup1\Install2.wim refers to the image file Install2.wim in the group ImageGroup1.

PXE Services

The Windows DS PXE server is built on a unified and scalable architecture. As shown in Figure 3, it uses plug-ins to provide access to the data store. The PXE server supports one or more plug-ins, and each plug-in can use any data store. Windows DS provides a default BINL plug-in, as shown earlier in Figure 10-1.

Developers can use published APIs to create PXE server plug-ins. You can find these APIs in the Windows Vista SDK. The SDK also includes samples that developers can use to create their own plug-ins. For example, a developer can create a PXE server plug-in that works without requiring Active Directory and reads settings from a Microsoft SQL Server database.

Management

Windows DS provides two management tools that significantly simplify management tasks. The first tool is an MMC console that provides a graphical user interface for common management tasks. After installing Windows DS, you start this console by clicking Windows Deployment Services in the Administrative Tools folder of the Start menu (a second console, Windows Deployment Services Legacy, is for configuring legacy RIS installations). Examples of common tasks include adding images and configuring server settings. The second tool is Wdsutil. Wdsutil provides all of the management features that the console provides and more. It has a command-line interface that you can use to script management tasks. Both tools use the management API that Windows DS provides, and both tools enable remote administration.

Other management utilities include:

• Capture utility The Windows DS capture utility captures images to the .wim file format. It includes a light version of the ImageX /capture functionality and provides a GUI for it. You can use this to add the resulting .wim file to the image store.

• Active Directory Users and Computers extension You can use this extension to administer legacy RIS functionality and configure settings on the Remote Install tab of computer accounts.

• Risetup and Riprep Windows DS provides updated versions of Risetup and Riprep for upgrade scenarios (available for Windows Server 2003 only).

The Windows DS management console (Figure 4) provides significant administrative control. You can add and remove servers. You can configure a variety of options, including computer naming rules, DHCP settings, PXE response settings, and so on. Of course, you can add and remove installation and boot images. You can also organize images into image groups. The Windows DS management console gives you full control over the image groups and images you add to it. You can configure permissions for each image group and individual images, too. You can also associate an answer file with each individual image. The Windows DS management console helps you better manage images for different platforms. For example, you can associate different boot programs and boot images with the x86, x64, and ia64 platforms. You can also associate a global answer file with each platform.

Figure 4. Windows DS Management Console.

Client

The Windows DS client is a special version of Windows Setup that only runs within Windows PE. In other words, when you deploy Windows Vista to the destination computer using Windows DS, the Windows DS client runs within Windows PE on the client computer. This approach allows deployment of Windows Vista as well as mages for previous versions of Microsoft Windows.

The Windows DS client drives the setup experience as follows:

• Language selection For Windows Vista, the client prompts the user to choose a language. This choice applies to the setup user interface and the operating system installation. The user can also install additional language packs (Windows Vista Enterprise, Windows Vista Business, and Windows Vista Ultimate editions only).

• Credentials gathering The client prompts the user for required credentials.

• Image selection The client displays a list of images available to the user, and then allows the user to choose an image to install on the destination computer.

• Disk configuration The client allows the user to partition and format the destination computer’s hard disks. The client provides the same options as Windows Setup.

However, you can automate all of the settings that the client prompts for. To automate these settings, you use Microsoft Windows System Image Manager (Windows SIM) to create an Unattend.xml file.

Operating Modes

To provide a clear path between legacy RIS functionality and the new Windows DS functionality, Windows DS supports three modes:

• Legacy mode This mode uses OSChooser and RIPREP (sector-based) images. This mode is compatible with RIS. Moving from RIS-only functionality to legacy mode happens when you install the Windows DS update on a server running RIS.

• Mixed mode This mode supports both OSChooser and Windows PE for boot environments and RIPREP and ImageX imaging. Moving from legacy mode to mixed mode happens when you configure Windows DS and add .wim image files to it.

• Native mode This mode supports only the Windows PE boot environment and ImageX image files. The final move to native mode occurs after you have converted all legacy images to the .wim image file format and have disabled the OSChooser functionality.

Your choice of operating mode will depend on which client operating systems you are deploying and what your investment has been into legacy RIPREP images. You don’t need to abandon your current deployment images; operating in mixed mode allows you to continue to deploy legacy RIS images from OSChooser. It also allows you to deploy new .wim images of Windows Vista using Windows PE.

The mode used by Windows DS is not a simple selection in a dialog. Each mode is activated in a specific way. The following sections describe each mode in more detail and how to configure each mode.

Legacy Mode

In Windows DS, legacy mode is functionally equivalent to that of RIS (Windows DS binaries with RIS functionality). In legacy mode, only the Client Installation Wizard (OSChooser) will be present as the boot operating system. Therefore, only RISETUP and RIPREP images are supported. You will not be using the new Windows DS management tools; rather, legacy RIS utilities will be the only way to manage the server. Legacy mode is only available on Windows Server 2003.

You configure legacy mode by first installing RIS on Windows Server 2003 and optionally adding legacy images to it. Then, you install the Windows DS update. You do not configure Windows DS by using Wdsutil or the Windows DS management console.

To configure Windows DS in legacy mode

Mixed Mode

Mixed mode describes a server state in which both OSChooser and Windows PE boot images are available. In mixed mode, access to the old RISETUP and RIPREP images is possible through OSChooser. Additionally, you can access the new .wim image files via a Windows PE boot image. A boot menu allows users to choose RIS or Windows PE. You will use legacy management tools to manage RISETUP and RIPREP images and the new Windows DS management tools to manage all facets of the server, including the .wim image files. WDS mixed mode is only available on Windows Server 2003.

You configure mixed mode by first installing RIS on Windows Server 2003 and adding legacy images to it. Then, you install the Windows DS update. Last, you run Wdsutil or use the Windows DS management console to configure Windows DS and then optionally add .wim images to the image store.

To configure Windows DS in mixed mode

Native Mode

Native mode describes a Windows DS server with only Windows PE boot images. In this mode, OSChooser is not available, and Windows DS only deploys .wim image files to client computers. You use the Windows DS management console or Wdsutil to manage Windows DS in native mode. Native mode is available on both Windows Server 2003 and Windows Server Code Name “Longhorn.” Native mode is the only mode that Windows Server Code Name “Longhorn” supports.

To configure Windows DS in native mode

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