PC Power Down, Energy Saving

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<< 3. Server Index PC Power Down - Client Guide >>
4. Deployment How to deploy PC Power Down

4.1. Wake On Lan

4.1.1. Introduction
Wake On Lan (WoL) is a feature that allows computers to be woken via a "Magic Packet". The computer is configured to reserve power to the Network Interface Card (NIC), allowing it to receive the Magic packet and trigger the computer to turn on.

The Magic packet is a simple UDP that contains the MAC address of the targeted computer. It is broadcasted to every computer on port 7.

4.1.2. Configuring WoL
The computer must support WoL and be configured correctly to wake up. This does not affect powering down, which is where the power savings are made.

Most modern computers support WoL, the installer should configure the NIC driver properties on Windows. However the BIOS settings may need to be adjusted. If a PCI NIC is used then it should be PCI 2.2 compliant.

BIOS settings are different for every motherboard which makes a definitive guide rather difficult. There should generally be a power management option. Look for any settings that mention reserving power to the network card / PCI slots, power management states, WoL or Magic Packets.

Although the installer should configure NIC properties it is not always successful as the properties aren't standardised and vary between network card manufacturers.

To manually enable the network card from Windows, load up device manager and view the properties of the NIC. Under the power management tab there should be settings relating to reserving power to the NIC. As these settings can vary between network card manufacturers, please enable settings that seem appropriate. A screenshot of the settings is shown below.

4.2. Compatibility issues

As mentioned in section 4.1.2, client machines must support Wake on Lan and have it enabled.

As it would be extremely time consuming to check each individual computer, it is therefore recommended to group computers into similar groups and test one computer in each group.

For example your site may have 700 computers, but it is likely that they were purchased in batches. So categorise your computers into brand and model, as shown below.

• 320 "Dell Vostro 200MT"
• 210 "HP Pavillon p6300"
• 100 "HP Pavillion Elite HPE-100"
• 70 "Packard Bell iMedia A2620UK"

You will only need to test 4 different computers to determine if WoL is supported or needs configuring.

4.3. Remote configuration

It is often impractical to manually configure each computer. This section will discuss possible solutions to automating the configuration. We cannot offer support on this and any remote configuration is carried out at your own risk.

The installer uses a Visual Basic Script (VBS) to enable the NIC properties. However if this does not work on some of your computers then it may be possible to find or customise a script to enable these settings. Once working this script can then be remotely applied across the network using a login script or tools such as PsExec.

Another possibility is to use a registry monitor tool while you manually edit your NIC properties, this will indentify which settings are required. You can then apply these registry updates remotely.

Some PC vendors such as Dell and HP offer BIOS tools, allowing BIOS to be updated or configured remotely. This should however be treated with caution. Although unlikely a power outage during a BIOS update could cause permanent damage to the computer.

4.4. Hibernation

This Windows feature is enabled on installation. To manually enable it through the command prompt, type the command "powercgf.exe /hibernate on".

As hibernate saves RAM to the hard drive there must be sufficient space available.

There may also be hibernate issues on XP without SP3.

4.5. Recommended install plan

As with any software it’s a good idea to test it on a few computers before rolling it out to all. If possible install on each type of computer at the site, see section 4.2.

Ensure that port 4455 TCP is open on firewalls and switches for the client software to communicate with the server. Port 7 UDP is used by the server to send wake ups.

Once tested, uninstall the client from the test computers, ensuring a restart.

Add a DNS record to map "pcpserver" to the IP address of the PC Power Down server.

Then push out software using an MSI, see our MSI guide.

The server will add each client to its database upon client contact. Organise into groups and create schedules.

Last updated by Administrator (admin)  on Feb 21 2011  at 5:38 PM
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