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Sustainable Computing Enforce Power Management Settings in your Organization with Group Policy
Frank Koch, Mike Stephens, and Michael Walsh
Microsoft offers a number of solutions that can help IT Professionals reduce the energy footprint of their infrastructure.
With Microsoft System Center Configuration Manager 2007, you can easily monitor and capture the configuration information of servers, desktops, and laptops across your network. In doing so, Configuration Manager utilizes Desired Configuration Management (DCM) to evaluate systems and determine whether they are configured in accordance with corporate requirements.
DCM supports imported configuration packs, which are best practices created by Microsoft and other software vendors to identify common configuration errors for applications and operating systems. For instance, the August 2008 release of the Microsoft Assessment Configuration Pack for ENERGY STAR Power Management allows administrators to assess display and hibernation settings on Windows XP and Windows Vista to determine whether systems adhere to the ENERGY STAR guidelines set by the United States Environmental Protection Agency (EPA). These guidlelines are as follows:
- Computers must enter system standby or hibernate after 30 to 60 minutes of inactivity.
- Monitors must enter sleep mode after 5 to 20 minutes of inactivity.
Using the new configuration pack, administrators can also ensure that a warning notification report is created if screen savers are not disabled. (Screen savers should not be used if you are trying to reduce your footprint.)
Bring Windows Server 2008 and Windows Vista Power Management Settings into Compliance
Windows Server 2008 and Windows Vista are configured by default to take advantage of energy-efficient features. They also allow you to use Group Policy to centrally manage a greater number of features than Microsoft Windows Server 2003. With the latest Microsoft operating systems, all power management settings support Group Policy and ship with more than 35 power management settings that administrators can use to create the power management strategy that best suits their needs. They can then use Group Policy to roll out their energy settings.
As you probably know, Group Policy allows administrators to define specific configurations for groups of users and computers. These settings are specified through the Group Policy Object Editor (formally known as GPedit) and contained in a Group Policy object (GPO), which is in turn linked to Active Directory containers, such as sites, domains, or OUs.
In this way, Group Policy settings are applied to the users and computers in those Active Directory containers. IT professionals therefore can configure a user's work environment once and rely on the system to enforce the policies as defined.
To take advantage of Group Policy, you must acquire the Group Policy Management Console (GPMC), which is a comprehensive administrative tool for Group Policy management. GPMC comes with both Windows Server 2008 and Windows Vista. Note that Windows Vista SP1 requires you to download the Microsoft Remote Server Administration Tools for Windows Vista. This free download includes an updated version of GPMC. The first version of GPMC (version 1.0) is meant for configuring Group Policy in a Windows Server 2003 and Windows XP.
The advantage of using Group Policy to configure power settings is that Windows Server 2008 and Windows Vista will use the values specified by Group Policy, preventing end users from changing the settings. If the user attempts to make a change, the Windows Vista Power Options Control Panel informs the user that the selected power policies may not be changed because they are enforced by the administrator.
While Windows Vista does let the user switch between power plans (such as battery saver and balanced), the administrator can use Group Policy to enforce specific settings within those power plans. Even if the user changes power plans, the Group Policy power setting is enforced.
To enforce a power setting using Group Policy, administrators must use the Management Console to edit a new or existing GPO. The power management policies are located in Power Management, under Computer Configuration | Administrative Templates | System | Power Management. Note that there are no power management policies under User Configuration in Windows Vista, and each power setting lets you specify separate values for when the computer is plugged-in (AC) or running on battery power (DC).
For a complete description of how to deploy power management settings to bring your Windows Vista systems into compliance, see the May 2008 installment of this column, "Conserving Energy with Group Policy".
Bring Windows Server 2003 and Windows XP Power Management Settings into Compliance
If you find that you have Windows Server 2003 and Windows XP systems that do not meet the desired power management requirements, you can then use Group Policy Preferences to bring those systems into compliance. To use this functionality, you need the GPMC.
You'll also need to acquire the client-side extensions that allow Windows Server 2003 and Windows XP to process GPOs that contain preference configuration data. These are also available as free downloads for Windows Server 2003, Windows XP, and Windows Vista.
Group Policy Preferences offer two items that can be used to configure power management settings on Windows Server 2003 and Windows XP. The Power Schemes preference allows you to create, modify, and delete power schemes. In other words, it allows administrators to configure Windows XP clients to use one of the pre-existing power schemes, modify the settings included in one of the pre-existing power schemes, or deploy a custom power scheme. The Power Options Preference provides a way to configure hibernation, configure prompting for a password when the computer resumes, and set the Power button action for mobile computers.
When you view properties on a Power Option Preference item, the configuration screen closely resembles the properties dialog provided by the OS.
There are some important points you should keep in mind when working with these Preference items. First off, Preferences allow administrators to choose which settings they want to control and which settings they do not want to configure. And, an important point, Preference items are not Group Policy settings. They are not enforced but rather just applied. Users with proper privileges can change a Preference setting to another selection, though the setting will return on the next Group Policy refresh unless it has been configured otherwise.
Power Schemes has the same enable/disable feature as Power Options and behaves in the same fashion. Power Schemes provides settings for two scenarios: Plugged-in and Running on batteries. You can use Power Schemes to define the time-out settings for turning off monitors, hard disks, system standby, and system hibernate.
The Power Schemes action field determines the action that Group Policy processing applies to the specific preference item. There are four actions to choose from:
- Create generates a new Power Scheme. If a Power Scheme with the same name already exists on the target computer, the Preference item does nothing.
- Delete will delete a Power Scheme.
- Update will update Power Schemes. If you try to update a Power Scheme that does not exist on the target computer, then a new Power Scheme is created with that name.
- Replace is very similar to Update. Whereas Update simply updates the enabled settings on the existing Power Scheme, leaving all other settings as they were, Replace actually deletes the named Power Scheme from the computer and creates a new Power Scheme based on the settings specified in the Power Scheme Preference item.
Here are some other things you should keep in mind:
- Power management Preference items can target both computer and user configurations. This means the user settings, possibly from another Preference item, will replace the current power settings.
- Local Administrators are Administrators. Administrators can change their power configuration, but standard users cannot.
- When Group Policy applies power management Preference items, those items become the current power management scheme—even after the user logs off.
- Power management Preference items support background refresh and, therefore, settings can change.
Aside from Group Policy Preferences, Windows Server 2003 administrators can also use a manual command line tool called Powercfg (support.microsoft.com/kb/324347). With this tool, an administrator can access the settings from the Power Options tool in the Control Panel and set those settings from the command line.
Powercfg also extends some settings that are not available in Control Panel, although Powercfg does not let you configure all the settings in the Power Options tool. Unfortunately, this tool doesn't let you centralize configuration of power management settings and, therefore, it is not the best option for enterprise administrators. With the right processor and driver, though, System Center Configuration Manager can overcome this shortcoming by centrally deploying an updated power profile (and any necessary drivers) across all Windows Server 2003 servers.
Frank Koch works for Microsoft.
Mike Stephens works for Microsoft.
Michael Walsh is the Senior Environmental Product Manager at Microsoft.