Developing Disk Images : Editing a Build’s Task Sequence

BDD 2007 uses a task sequencer to run the task sequence. The task sequencer runs the task sequence from top to bottom in the order specified. Each task in the sequence is a step, and steps can be organized in to groups and subgroups. When you create a build in Deployment Workbench, Deployment Workbench creates a default task sequence for the build. A key feature of the task sequence is that it stores state data, or variables, on the destination computer. These variables persist, even across reboots. The task sequencer can then use these variables to test conditions and possibly filter tasks or groups. The task sequencer can also restart the computer and gracefully continue the task sequence where it left off. These are important characteristics when driving a deployment process from beginning to end.

Task sequences contain the following types of items:

• Tasks Within a task sequence, tasks do the actual work. Tasks are commands that the task sequencer runs during the sequence, such as partitioning the disk, capturing user state, and installing the operating system. In the default task sequence, most tasks are commands that run scripts.

• Groups The task sequence can be organized into groups, which are folders that can contain subgroups and tasks. Groups can be nested as necessary. For example, the default task sequence puts tasks in groups by phase and deployment type.

You can filter both tasks and groups, including the groups and tasks they contain, based on conditions that you specify. Groups are especially useful for filtering, because you can run an entire collection of tasks based upon a condition such as the deployment phase or type of deployment.

To edit a build’s task sequence

1.	In the Deployment Workbench console tree, click Builds.
2.	In the details pane, right-click the build you want to edit, and then click Properties.
3.	Click the Task Sequence tab, edit the task sequence as described in Table 1, and then click OK. Table 1. Editing a Build’s Task Sequence To Use these steps Add a group In the task sequence, select the item beneath which you want to create a new group, click Add, and then click Group. Deployment Workbench creates and selects a new group called New Group. Add a task In the task sequence, select the item beneath which you want to create a new task, click Add, and then click Task. Deployment Workbench creates and selects a new task called New Task. Add a reboot In the task sequence, select the item beneath which you want to add a reboot, click Add, and then click Reboot. Deployment Workbench creates and selects a new task that restarts the destination computer. A reboot is an ordinary task that runs the command smsboot.exe /target:HD to restart the computer and continue the task sequence. Add an application In the task sequence, select the item beneath which you want to add an application installation, click Add, and then click Application, ApplicationName, where ApplicationName is the name of the application you want to install. Deployment Workbench creates and selects an installation task for the application using the information provided when adding the application to the distribution share. An application is an ordinary task that runs the command specified when the application is added to the distribution share.

To edit an item in a build’s task sequence

To remove an item in a build’s task sequence

To reorder an item in a build’s task sequence

Configuring Group and Task Properties

In the task sequence, every group and task has a Properties tab. Each group and task has a name and description that you can edit on the Properties tab. Tasks also have a command line and a starting folder location that you can edit. The following list describes what you see on the Properties tab:

• Name In the Name box, type a short, descriptive name for the group or task. During deployment, this name appears in the task sequencer’s status window.

• Description In the Description box, type a description of the group or task.

• Command Line (tasks only) In the Command Line box, type the command to run at this step in the task sequence. Include any command-line arguments. Environment variables are also permitted in command lines.

• Start In (tasks only) In the Start In box, type the path in which to start the command. This path specifies the current working directory for the command. If you do not provide a path in this box, the paths in the Command Line box must be fully qualified or the command must be in the path.

Configuring the Options Tab

Groups and tasks have the following settings on the Options tab (shown in Figure 1):

• Disable This Step Select the Disable This Step check box to disable the task or group, including all groups and tasks it contains.

• Success Codes (tasks only) List the return codes that indicate successful completion. The Windows Deployment Wizard determines whether a task completed successfully by comparing its return code to each code in the Success Codes box. If it finds a match, the task completed successfully.

• Continue On Error If an error occurs in the current task, select the Continue On Error check box to continue with the next step in the task sequence. If you clear this check box, the Windows Deployment Wizard stops processing and displays an error message if the task or group did not complete successfully.

Figure 1. The Options tab.

Additionally, on the Options tab, you can filter the group or tasks based on conditions specified in the Conditions list. If the condition evaluates to true, the group or task runs. If the condition evaluates to false, the group (and all of the groups and tasks it contains) or task does not run. See the following sections for more information about conditions you can add to the Conditions list.

Task Sequence Variables

Task sequence variables allow you to compare a variable to a static value using a variety of conditions, such as equal, greater than, and less than. The task sequencer maintains numerous variables that you can use in these tests. For example, the task sequencer defines a variable called DeploymentMethod that indicates the method of deployment. One possible value of DeploymentMethod is OSD. For a complete list of variables that the task sequencer maintains, see the Configuration Reference in BDD 2007.

To add a variable to an item’s Conditions list

If Statements

Use If statements to combine variables into bigger expressions. For example, create an If statement that evaluates to true only if all the conditions it contains are true. (This is the same as a logical AND.) Create an If statement that evaluates to true if any of the conditions it contains are true. (This is the same as a logical OR.)

To add an If statement to an item’s Conditions list

If you chose All Conditions, all variables added must evaluate to true for the group or task to run. If you chose Any Conditions, the group or task will run if any one of the variables added evaluates to true.

Operating System Versions

The task sequencer allows you to filter tasks and groups based on the computer’s current operating system. For example, you can choose to run a preinstallation task only if the destination computer is currently running Windows XP Professional SP2.

To add an operating system filter to an item’s Conditions list

WMI Queries

The task sequencer allows you to filter tasks and groups based on WMI queries. The WMI query must return a collection. If the collection is empty, the result evaluates to false. If the collection is not empty, the result evaluates to true. The following are some sample WMI queries you could use to filter tasks in the task sequence:

• SELECT * FROM Win32_ComputerSystem WHERE Manufacturer = ‘Dell Computer Corporation’. This is true only if WMI reports the computer’s manufacturer as Dell Computer Corporation.

• SELECT * FROM Win32_OperatingSystem WHERE OSLanguage = ‘1033’. This is true only if WMI reports the operating-system language as 1033.

• SELECT * FROM Win32_Service WHERE Name = ‘WinMgmt’. This is true only if the WinMgmt service is available.

• SELECT * FROM Win32_Processor WHERE DeviceID = ‘CPU0’ AND Architecture = ‘0’. This is true only if the processor architecture is x86.

• SELECT * FROM Win32_Directory WHERE Name = ‘D:\Somefolder’. This is true only if D:\Somefolder exists on the computer.

To add a WMI query to an item’s Conditions list