Windows Server 2003's new Automated Deployment Services (ADS) lets you remotely deploy and manage new Windows 2003 or Windows 2000 Server installations through a central Microsoft Management Console (MMC) snap-in or Windows Management Instrumentation (WMI) scripts. As part of the Microsoft Dynamic Systems Initiative (DSI), ADS is designed for high-bandwidth datacenter environments and combines several existing technologies—including a Preboot Execution Environment (PXE) server, volume-imaging tools, Deployment and Administration agents, a WMI interface, and command-line tools—to provide a framework for mass server deployment and administration. (By volume imaging, I mean a technique that captures a hard disk volume's contents to a file that you can then copy to similar hardware. ADS is Microsoft's first volume-imaging technology and complements other Microsoft deployment technologies such as Remote Installation Services—RIS.) Let's take a look at ADS's architecture and operations and a basic ADS-driven deployment.
The ADS Architecture
Figure 1 shows ADS's basic architecture. At the top of the architecture are various ADS management interfaces—the MMC ADS snap-in, command-line tools, and customized WMI scripts and applications—that interact with ADS's core service through WMI. The ADS snap-in lets you manage the ADS server (i.e., the server on which you install ADS) as well as the various systems you want to image, deploy, and manage. The command-line tools basically perform the same functions that you can invoke from the ADS snap-in. (The ADS online documentation, which is available at http://www.microsoft.com/windowsserver2003/technologies/management/ads/default.mspx, includes a complete list of the available command-line tools and their purposes.) During setup, ADS adds several WMI classes to the WMI Common Information Model (CIM) repository; developers can use these classes to create customized ADS applications or scripts. You must run ADS (which you can download at http://www.microsoft.com/windowsserver2003/techinfo/overview/adsbenefits.mspx) on a Windows 2003, Enterprise Edition or Windows 2003, Datacenter Edition system.
ADS comprises three services: the Controller service, Network Boot Services (NBS), and Image Distribution service. These services handle the sequencing of jobs, PXE boot requests, and volume imaging. NBS includes the PXE service and is mainly responsible for the ADS Deployment Agent's boot capability. The Image Distribution service supports the downloading or uploading of images through the Deployment Agent.
ADS provides two agents: a Deployment Agent and an Administration Agent. The Deployment Agent, which NBS boots from the network through PXE, implements a small subset of Windows to let you deploy systems from the ADS server. (This agent includes several Windows 2003 components, so you'll need the Windows 2003 CD-ROM during ADS setup.) Among other things, the Deployment Agent lets you download a disk image from or upload a disk image to the ADS server. The Deployment Agent executes specific tools and commands through XML files, which define a sequence of operations for typical jobs (e.g., partitioning the disk, changing the registry's image content, copying extra files from the ADS server onto a deployed system's hard disk). These jobs are known as ADS task sequences. (For more information about how ADS executes these sequences, see the Web-exclusive sidebar "ADS Sequence Files," http://www.winnetmag.com, InstantDoc ID 41399.)
The Administration Agent runs as a service in the deployed OS. You must install this agent in the OS that you plan to deploy before you take an image of that OS. You can use the agent to perform various management tasks (e.g., execute Windows 2003 tools such as the WMI Command-line—WMIC—tool, use WMI or Active Directory Service Interfaces—ADSI—to start Windows Script Host—WSH—scripts) in the deployed OS from the ADS server. You can also execute, through the Administration Agent, any third-party scripting engines that you install in the image (so long as any components necessary to execute a task are also installed in the deployed image). Although you can use the agent to execute most traditional management tools, be sure that you carefully select the security context in which you run the agent (i.e., whether you run the service from the Local System account or a domain account). If you don't need network connectivity, running the agent in the local security context is best.
ADS logs all its job activities to a Microsoft SQL Server 2000 or Microsoft SQL Server Database Engine (MSDE) database. ADS comes with MSDE, which you can use if you don't have SQL Server. If you require a more scalable architecture or want to use a decentralized SQL Server database to store ADS information, you can specify database-access parameters during ADS setup.
ADS also provides a set of interactive volume-imaging tools that you can use to mount an image as a mapped volume so that you can transparently explore and update the image content as if it were on the local hard disk. This capability lets you modify an existing image without needing to recapture the volume. You can also use the imaging tools to capture or restore an image from which a deployed system can boot. For example, you can use these tools to boot a target system from Windows Preinstallation Environment (WinPE), then capture the volume to create an image on or download an image from the ADS server. (WinPE is a "light" version of Windows that you can boot from a CD-ROM to access a Windows command prompt. WinPE supports technologies such as WSH, HTML applications, and ADO, which permit script execution. WinPE is available only to Enterprise Agreement—EA—or Select License customers who've signed up for Software Assurance—SA. You can find more information about WinPE at http://www.microsoft.com/licensing/programs/sa/support/winpe.asp.) However, this method requires you to be physically present at the target system to boot WinPE and doesn't support multicast Trivial FTP (TFTP), which can improve performance. Using the Deployment Agent to copy and restore images is a better method because the agent lets you use multicast TFTP to broadcast the image to a group of machines, without requiring you to visit each target system.
Installing ADS and Capturing an Image
Now that you have an idea of the ADS architecture, let's take a look at the process of installing and setting up ADS and capturing the OS image that you want to deploy. The examples in this article provide a basic approach—more complicated deployments are beyond the scope of the article—but are sufficient to give you an idea of the way ADS works.
To install ADS, download it to a folder on a Windows 2003 Enterprise or Windows 2003 Datacenter server, then run the executable. The examples in this article assume that you'll accept the option to install MSDE and that you'll accept all default installation parameters for ADS. (You'll need the Windows 2003 CD-ROM during the setup process.) After the Setup program is complete, go to C:\program files\microsoft ads\samples\sequences and start the create-templates.bat file to register the default ADS sequences in the ADS server database.
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