Power-Saving for Power-Saving for £0£0

Lisa NelsonLisa Nelson

University of LiverpoolUniversity of Liverpool

The ProblemThe Problem

Computers often left on all the time, Computers often left on all the time, regardless of whether they are in regardless of whether they are in useuse

Changing people’s behaviour is Changing people’s behaviour is difficultdifficult

Need an automatic power-saving Need an automatic power-saving mechanismmechanism

The GoalThe Goal

Reduce power consumptionReduce power consumption When PCs are idleWhen PCs are idle Without risking losing dataWithout risking losing data At no costAt no cost

Use Built-In Windows Use Built-In Windows Capabilities?Capabilities?

Hibernate?Hibernate? Excellent power reductionExcellent power reduction Can have issues in network environmentsCan have issues in network environments

Standby?Standby? Good power reductionGood power reduction Same potential issues with network Same potential issues with network

environmentsenvironments Power down hard disks?Power down hard disks?

In practice, did nothingIn practice, did nothing Stores settings for the current user!Stores settings for the current user! No management by policy!No management by policy!

Use Third-Party Utilities?Use Third-Party Utilities?

CostCost Client utilitiesClient utilities

E.g. LocalCoolingE.g. LocalCooling All limited to underlying Windows All limited to underlying Windows

capabilities = same problemscapabilities = same problems Centrally-managed utilitiesCentrally-managed utilities

Can only schedule = less aggressiveCan only schedule = less aggressive

ConclusionsConclusions

Shut downShut down But only when nobody is logged onBut only when nobody is logged on Not very aggressive, but safeNot very aggressive, but safe

Excellent for walk-up computersExcellent for walk-up computers Can be done with batch files and Can be done with batch files and

freeware utilities for £0freeware utilities for £0

How It WorksHow It Works

Setup batch file:Setup batch file: Create a scheduled task to run power-saving Create a scheduled task to run power-saving

batch file (as the System user) after N batch file (as the System user) after N minutes idleminutes idle

Copy power-saving batch file somewhere Copy power-saving batch file somewhere locallocal

Also copy two freeware utilitiesAlso copy two freeware utilities Power-saving batch file:Power-saving batch file:

Determine whether anybody is logged onDetermine whether anybody is logged on If not, shut downIf not, shut down

Possible ProblemsPossible Problems

Some people may legitimately need to Some people may legitimately need to opt outopt out Running grid applications with nobody Running grid applications with nobody

logged onlogged on Acting as a serverActing as a server So supply a discretionary opt-out mechanismSo supply a discretionary opt-out mechanism

Psshutdown flagged as dangerousPsshutdown flagged as dangerous NOT a problem: erroneously shutting NOT a problem: erroneously shutting

down when somebody is logged ondown when somebody is logged on

Our ResultsOur Results

No problemsNo problems Statistics:Statistics:

Shutdowns per day: ~4,500Shutdowns per day: ~4,500 Total computers participating: ~3,500Total computers participating: ~3,500 Average daily downtime: 33,350 hours = Average daily downtime: 33,350 hours =

>1,000,000 hours per month!>1,000,000 hours per month! Average daily MW (assuming 100 W): 3.3 Average daily MW (assuming 100 W): 3.3

MWMW Average daily kg COAverage daily kg CO22 (0.43 kg/kW): 1,400 (0.43 kg/kW): 1,400

kgkg

Want to Try It?Want to Try It?

E-mail me: E-mail me: lisa.nelson@liverpool.ac.uklisa.nelson@liverpool.ac.uk

Or go toOr go to

http://pcwww.liv.ac.uk/http://pcwww.liv.ac.uk/powerdownpowerdown

LimitationsLimitations

No reportingNo reporting Not very flexibleNot very flexible Inconvenient to modify after rolloutInconvenient to modify after rollout Not very effective for staff-style Not very effective for staff-style

working patternsworking patterns

The Big LimitationThe Big Limitation

What if you want to do more?What if you want to do more?

PowerMan: OverviewPowerMan: Overview

Single executableSingle executable Copy into place and Copy into place and

run POWERMAN run POWERMAN INSTALLINSTALL

Runs as a serviceRuns as a service Controlled by Controlled by

group policygroup policy Easy to modifyEasy to modify

Built-in reportingBuilt-in reporting

PowerMan: FeaturesPowerMan: Features

Control monitor, disk, computer idle Control monitor, disk, computer idle timeoutstimeouts

Actions: log off, stand by, hibernate, power Actions: log off, stand by, hibernate, power offoff

Specify different actions and timeouts for:Specify different actions and timeouts for: When a user is logged on vs. no userWhen a user is logged on vs. no user Running on AC vs. DCRunning on AC vs. DC

Exceptions (files or processes, Server Exceptions (files or processes, Server service)service)

Scheduled wake and shutdownScheduled wake and shutdown

PowerMan: ReportingPowerMan: Reporting

Built-in reportingBuilt-in reporting Easily see overviews or detail down to Easily see overviews or detail down to

individual computersindividual computers Easy to identify your culpritsEasy to identify your culprits

How We Use PowerManHow We Use PowerMan Walk-up: Walk-up:

Force logoff after 3 hrs Force logoff after 3 hrs idleidle

Hibernate after 10 mins Hibernate after 10 mins when nobody is logged onwhen nobody is logged on

Staff:Staff: Can choose what to do Can choose what to do

when idle:when idle: When a user is logged on; When a user is logged on;

e.g. stand by after 30 e.g. stand by after 30 minutesminutes

When nobody is logged When nobody is logged on; e.g. hibernate after on; e.g. hibernate after 10 minutes10 minutes

ResultsResults

Where We Are NowWhere We Are Now

All our power-saving is now being All our power-saving is now being done by PowerMandone by PowerMan Walk-up: <1 hr idle/dayWalk-up: <1 hr idle/day Staff:Staff:

Still in progress – ~2000 computers yet to Still in progress – ~2000 computers yet to choose settingschoose settings

But have cut idle time by 25%; anticipate But have cut idle time by 25%; anticipate eventually 75%eventually 75%

Previously 1,000,000 hrs/month; Previously 1,000,000 hrs/month; anticipate eventually 2,000,000anticipate eventually 2,000,000

Want to Try It?Want to Try It?

E-mail: E-mail: info@datasynergy.co.ukinfo@datasynergy.co.uk

Or go toOr go to

http://www.datasynergy.co.ukhttp://www.datasynergy.co.uk