Automating the process minimizes the chance that a careless mistake will result in the operating system deployment process needing to be restarted from the beginning. In this lesson, you’ll learn about WDS, understand different image types used with automated operating system deployment technologies, and learn how to create answer files so that operating system deployment can be deployed without requiring direct administrator attention.
- Create answer files.
- Manage Windows Deployment Services (WDS).
- Deploy discover, boot, and install images.
Automating installation
When performing an operating system installation, you spend far more time watching process bars than you do inputting configuration information. If you automate server operating system deployment, you can minimize the amount of time you have to spend watching the operating system install. Automating the process also minimizes the chance of configuration mistakes that might occur when bored administrators get distracted during the deployment process.
There are two different ways to automate server operating system deployment:
- Answer files You can start an operating system deployment and provide an answer file. The installation process uses the answer file to answer all necessary questions. A complex answer file can perform post–installation configuration tasks. The drawback of answer files is that they take time to configure properly. Once you get them working, though, they’ll save you many hours.
- Centralized deployment Rather than installing operating systems from a DVD or USB stick, you can use centralized deployment to perform simultaneous installations of the same operating system on multiple computers. Centralized deployment can even be used with answer files.
Configuring answer files
With answer files, you can automate the process of deploying Windows Server 2012. Instead of having to manually select specific installation options and perform post–installation configuration actions such as joining a newly deployed server to an AD DS domain, you can automate the process with answer files. During setup, Windows Server 2012 looks for a file on local and attached media named Autounattend.xml. If this file is present, Windows Server 2012 automatically uses the settings contained in the file to configure the new server deployment.
As its name suggests, Autounattend.xml uses the XML file format. Although it is certainly possible for you to manually edit this XML file using a text editor such as Notepad, this process is complicated, and you are likely to make errors that cause the file not to work. The Windows System Image Manager (known as Windows SIM) is a GUI-based tool that you can use to create an answer file. When using the tool, you must specify the image for which you want to create an answer file. Windows SIM then creates a catalog file for all the options that you can configure. After you configure all the settings that you want automated during installation and post-installation configuration, you can have the tool output an answer file using correct XML syntax. Windows SIM is included with the Windows Assessment and Deployment Kit (Windows ADK), which you can download from the Microsoft website.
To create an answer file using Windows SIM, perform the following steps:
- Download and install Windows ADK from the Microsoft website using the installation defaults.
- Copy the file \Sources\install.wim from the Windows Server 2012 installation media to a temporary directory on the computer on which you have installed Windows ADK.
- Open Windows SIM from the Start screen.
- In the Windows SIM interface, click File and then click Select Windows Image. Open the file Install.wim.
- Select which operating system image in the install image for which you wish to create an answer file.
- When prompted to create a catalog file, click Yes.
- Click File and click New Answer File.
- Use Windows SIM to select each component that you want to configure. Figure 1-5 shows how you can configure installation to join the contoso.com domain.
Configuring an answer file
Windows Deployment Services
WDS is a server role that you can deploy on computers running Windows Server 2012. WDS enables you to deploy operating systems, including but not limited to Windows 8 and Windows Server 2012, to computers over the network. WDS sends these operating systems across the network using multicast transmissions, so multiple computers receive the same operating system image while minimizing the use of network bandwidth. When you use multicast transmissions, the same amount of traffic crosses the network independently of whether you are deploying Windows Server 2012 to 1 computer or 50.
Deploying Windows Server 2012 through WDS involves performing the following steps:
- An operating system deployment transmission is prepared on the WDS server.
- The media access control (MAC) addresses of Pre-boot Execution Environment (PXE)–compliant network adapters are made available to the WDS server.
- The computers that are targets of the transmission boot using their PXE–compliant network adapters.
- These computers locate the WDS server and begin the operating system setup process. If the WDS server has been provisioned with an answer file, as shown in Figure 1-6, the setup completes automatically. If the WDS server has not been provisioned with an answer file, an administrator must enter setup configuration information.
Configuring unattended files
WDS requirements
WDS clients need PXE–compliant network adapters, which is rarely a problem because almost all modern network adapters are PXE–compliant. You can also use WDS to deploy Windows Server 2012 to virtual machines running under Hyper-V. The trick to doing this is to use a legacy rather than a synthetic network adapter when creating the virtual machine.
If you have a computer that does not have a PXE–compliant network adapter, you can configure a special type of boot image known as a discover image. A discover image boots an environment, loading special drivers to enable the network adapter to interact with the WDS server. You create the boot image by adding the appropriate network adapter drivers associated with the computer that can’t PXE boot to the Boot.wim file from the Windows Server 2012 installation media.
WDS has the following requirements:
- A Windows Server 2012 DNS must be present on the local area network (LAN). This is implied by the domain membership.
- An authorized Dynamic Host Configuration Protocol (DHCP) server must be present on the network. You can host WDS and DHCP on the same computer as long as you configure the options shown in Figure 1-7.
With Windows Server 2012, you can deploy WDS on a server that is not a member of an AD DS domain. This is a feature new to Windows Server 2012. You can’t deploy WDS on a server running Windows Server 2008 or Windows Server 2008 R2 unless that server is a member of an AD DS domain.
WDS and DHCP colocation settings
If you install WDS from the Add Roles And Features Wizard, you can configure these settings automatically. Although the WDS server does not require a static IP address, it is good practice to ensure that infrastructure roles such as WDS always use a consistent network address. You can install WDS on computers running the Server Core version of Windows Server 2012. To install WDS on a computer running the Server Core version of Windows Server 2012, import the ServerManager Windows PowerShell module using the following Windows PowerShell command:
Import-module ServerManager
And then install the role using the following command:
Install-WindowsFeature –IncludeAllSubFeature WDS
When installing WDS on Server Core, you have to specify the location of the source files or ensure that the server has a connection to the Internet, which enables them to be downloaded automatically. Although it is possible to manage WDS from Windows PowerShell, most administrators will use the graphical WDS Remote Server Administration Tools (RSAT) from a computer running Windows 8 or Windows Server 2012 with the graphical tools to perform this task. You can use Windows PowerShell to install the role on computers running the version of Windows Server 2012 that includes the graphical tools. When using Windows PowerShell to install WDS on a version of Windows Server 2012 that includes the graphical tools, also use the -IncludeManagementTools switch. To install WDS using the Add Roles And Features Wizard, select the Windows Deployment Services role.
Install WDS role
Managing images
Images contain either entire operating systems or a version of a special stripped-down operating system known as Windows PE. Windows PE functions as a type of boot disk, enabling a basic environment to be loaded from which more complex maintenance and installation tasks can be performed. WDS uses four image types: boot image, install image, discover image, and capture image.
- Boot image A special image that enables the computer to boot and begin installing the operating system using the install image. A default boot image, named Boot.wim, is located in the sources folder of the Windows Server 2012 installation media.
- Install image The main type of image discussed in this chapter. Contains the operating system as well as any other included components, such as software updates and additional applications. A default install image, named Install.wim, is present in the sources folder of the Windows Server 2012 installation media.
- Discover image This special image is for computers that cannot PXE boot to load appropriate network drivers to begin a session with a WDS server.
- Capture image A special image type that enables a prepared computer to be booted so that its operating system state can be captured as an install image. You add capture images as boot images in WDS.
To import an image into WDS, perform the following steps:
- Open the Windows Deployment Services console.
- Click Install Images. From the Action menu, click Add Install Image.
- Choose whether to create a new image group or to use an existing image group.
- Specify the location of the image file.
- In the Available Images page of the Add Image Wizard, select the operating system images that you want to add. When the image or images are added, click Next and then click Finish.
Configuring WDS
The installation defaults for WDS are suitable when you deploy the role in small environments. If you are deploying WDS in larger environments and do not choose to implement System Center 2012 Configuration Manager for operating system deployments, you might want to configure the options discussed in the following sections, which are available by editing the properties of the WDS server in the Windows Deployment Services console.
PXE response settings
With PXE response settings, you can configure how the WDS server responds to computers. As Figure 1-10 shows, you can configure WDS not to respond to any client computers (this effectively disables WDS), to respond to known client computers, or to respond to all computers but require an administrator to manually approve an unknown computer. Known computers are ones that have prestaged accounts in Active Directory. You can prestage computers if you know the MAC address of the network interface card (NIC) that the computer uses. Vendors often supply a list of MAC addresses associated with computers when you purchase those computers, and you can use this list to prestage computer accounts.
You use the PXE Response Delay setting when you have more than one WDS server in an environment. You can use this setting to ensure that clients receive transmissions from one WDS server over another, with the server configured with the lowest PXE response delay having priority over other WDS servers with higher delay settings.
Client Naming Policy
Client Naming Policy enables you to configure how computers installed from WDS will be named if you aren’t using deployment options that perform the action. You can also use the settings on this tab, to configure domain membership and organizational unit (OU) options for the computer account.
WDS Boot options
In the Boot options tab of the WDS server’s properties dialog box, you can configure how clients that PXE boot interact with the WDS server. You can also configure a default boot image for each architecture supported by WDS. By default, once a client has connected to a WDS server, someone must press the F12 key to continue deploying the operating system. In environments in which you are performing a large number of simultaneous deployments, requiring this level of manual intervention might substantially delay the deployment.
Multicast options
The default settings of WDS have all computers that join the multicast transmission receiving the installation image at the same speed. If you frequently deploy operating systems, you are aware that sometimes there are 1 or 2 computers that have network adapters that slow a transmission that should take only 15 minutes into one that takes half a day. You can configure the transfer settings on the Multicast tab, so that clients are partitioned into separate sessions depending on how fast they can consume the multicast transmission. You still have those slow computers taking a long time to receive the image, but the other computers connected to the transmission can complete the deployment more quickly.
Other options
Although you are less likely to need them, you can configure other options on the following tabs:
- Advanced tab You can configure WDS to use a specific domain controller and Global Catalog (GC) server. You can also configure whether WDS is authorized in DHCP. DHCP authorization occurs automatically when you install the WDS role.
- Network tab You can specify a User Datagram Protocol (UDP) port policy to limit when UDP ports are used with transmissions. You can also configure a network profile to specify the speed of the network, minimizing the chance that WDS transmissions will slow the network down.
- TFTP tab You can specify maximum block size and Trivial File Transfer Protocol (TFTP) window size.
Configuring transmissions
You use WDS transmissions to set WDS to transfer the operating system image across to PXE clients. When configuring a WDS transmission, you need to decide what type of multicast transmission you will perform in the Multicast Type page of the Create Multicast Transmission Wizard.
The difference between these options is as follows:
- Auto-Cast A transmission starts whenever a client requests the image. If another client requests the same image, the client will join the existing transmission, caching data from the current transfer, and then retrieving data that was transmitted before the client joined the transmission. This is the best option to use when you are performing one-off deployments.
- Scheduled-Cast You choose either to start the transmission when a specified number of clients have joined, or at a particular date and time. This is the best option to use when you are deploying the same operating system image to a large number of computers.
To configure a WDS transmission, perform the following steps:
- Open the Windows Deployment Services console, expand the WDS server from which you want to perform the deployment and click Multicast Transmissions. In the Action menu, click Create Multicast Transmission.
- Provide a name for the multicast transmission.
- In the Image Selection page, specify which operating system image you want to deploy using the transmission.
- In the Multicast Type page, specify whether you will use Auto-Cast or Scheduled-Cast. If you choose Scheduled-Cast, select the number of clients or the transmission start time.
Summary:
- Unless you are booting from a discover image, computers must be able to PXE boot to receive an operating system image from a WDS server.
- With boot images, computers with PXE-compliant network cards can load a preinstallation environment over the network from which it is possible to then load a minimal operating system.
- Install images contain the operating system as well as additional components, such as software updates and applications.
- Discover images are used with computers that do not have PXE-compliant network cards. Capture images are used when you want to capture a prepared operating system.
- Multicast transmissions enable the same installation image to be transmitted to multiple computers at the same time.
- If a WDS server also hosts the DHCP server role, it is necessary to configure the server to listen on a separate port and to configure DHCP option tag 60 for all scopes.
- You use Windows SIM to create unattended Windows Setup answer files. You can configure WDS with an unattended Windows Setup answer file to minimize the amount of interaction you need to perform when deploying Windows Server 2012.
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