Distribution refers to the way you store and transfer system files, device drivers, and software program files during an unattended installation. There are two types of distribution methods:

You can store files in a distribution share on a network share, and then transfer the files across the network to each of 17417n1314r the computers on which you are performing an unattended installation. This method works best when your destination computers are connected to a server by a reliable, high-bandwidth network.

You can store files on media - such as a CD, a DVD, or a floppy disk - and then transfer the files locally from the media to each of the computers on which you are performing an unattended installation. Typically, when you use this method, you use the operating system CD in conjunction with a floppy disk. The operating system CD contains the system files and device drivers; the floppy disk contains the answer file that is necessary to perform an unattended installation.

Figure 2. shows the steps you need to follow to choose a distribution method for
unattended installations.

Figure 2.    Choosing a Distribution Method

Evaluating Distribution Methods

Usually, unattended installations are performed with a distribution share. However, there are instances where a distribution share is not appropriate and you need to use media, rather than a distribution share, to perform an unattended installation. The guidelines in this section help you evaluate which distribution method is more appropriate for your organization's needs.

A distribution share contains the Windows XP Professional or Windows Server 2003 installation files, as well as any device drivers or other files that are required to customize the installation. The distribution share is structured hierarchically and resembles the folder structure on a computer running Windows Server 2003 or Windows XP Professional. The folder typically resides on a server to which your destination computers can connect. You typically create one distribution share for each operating system you are deploying.

By using a distribution share to perform an unattended installation, you can perform the following tasks:

A distribution share can contain special folders and files that are copied to a computer's hard disk during an unattended installation. For example, if you want to create a Scripts folder on drive C of your destination computers, you
can add the Scripts folder to your distribution share and it will automatically be copied to your destination computers during installation.

A distribution share contains folders for storing mass storage device drivers, HALs, and Plug and Play device drivers. The contents of these folders are copied to a computer's hard disk during an unattended installation.

A distribution share can contain a Sysprep folder, which can be used to store Sysprep files and the Sysprep.inf file. This is useful if you are performing image-based installations and you want to use unattended installation to create the master installations. In this case, you can add a Sysprep folder to the distribution share, and the Sysprep folder will automatically be created on the master installation when you perform an unattended installation.

Use a distribution share to perform your unattended installation if you want to:

Increase consistency. When you use a distribution share, you create a single source for system files, device drivers, and customized installation files that are copied to each destination computer, which ensures that each unattended installation is consistent throughout your organization.

Reduce administrative costs. All system files, device drivers, and customized installation files are stored in a central location, which reduces the cost of updating and changing system files and device drivers. For example, if you need to upgrade an existing device driver or add new device drivers, you only have to make the change in the distribution share. You do not need to create new answer files or create new floppy disks or CDs.

Control access to your installation files. You can secure a distribution share by using file and folder permissions, which lets you specify the users and groups who can gain access to your installation files. By default, in Windows Server 2003, the Everyone group is granted read-only permissions when a folder is shared. Therefore, when you create a distribution share you need to grant write permissions to all of the users who are responsible for configuring the distribution share.

In addition, distribution shares are useful if you are performing other types of automated installations, such as image-based or RIS installations. In these cases, you can use unattended installation with distribution shares to create consistent master installations that are easily modified and updated.

Despite the advantages, there are several disadvantages that might preclude you from using a distribution share. If any of the following conditions are true, you probably do not want to use a distribution share to perform unattended installations:

Slow network connections. Accessing a distribution share across a slow network connection, such as a dial-up connection or a slow wide area network (WAN) connection is overly time-consuming and impractical. It is recommended that you do not use a distribution share if your destination computers use a slow network connection to reach a distribution share.

Minimal file server capacity. Distribution shares are typically stored on file servers. If your file servers do not have sufficient capacity to store all of your distribution shares, or if your file servers cannot handle an increase in file throughput during your rollout, then you cannot use a distribution share. The minimum disk space required for a distribution share for Windows Server 2003, Standard Edition is 650 megabytes (MB).

Minimal number of unattended installations. You need to create, test, and maintain distribution shares. If you are performing only a few unattended installations, it is probably not cost-effective or efficient to use distribution shares. However, if you are performing image-based or RIS installations, and you are using unattended installations to create
only a few master installations, distribution shares are useful and cost-effective because a distribution share ensures consistency among master installations and makes it easy to make configuration changes.

If you choose to use distribution shares, you can save the distribution shares on multiple servers. This allows Setup to copy files simultaneously from several servers, thereby speeding up the file copy stage of Setup. In addition, you can use Distributed File System (DFS) to increase the availability of your distribution shares. For more information about copying installation files from multiple servers, see "Choosing Winnt32.exe Parameters" later in this chapter. For more information about DFS, see "Designing and Deploying File Servers" in Planning Server Deployments of this kit.