Do Any Companies Power Down at Night? 646
An anonymous reader writes "My Health Sciences Campus has about 8,000 desktop computers, and on any given night about half of them are left on. I know this because I track all the MAC addresses in case there is a virus outbreak. Aside from the current fad of 'being green', has anyone had any success in encouraging users to power-down at night? You could potentially eliminate running bots, protect yourself from the next virus outbreak, keep your data safe, etc. Do security concerns and power consumption issues matter enough to do this?"
We power down at weekends (Score:4, Informative)
Why power down? (Score:2, Informative)
Machines are woken from sleep to deploy updates, etc. Many of our desktops are able to accumulate 30 days of uptime before the next patchday.
Energy consumption is a non-issue. We don't pay much for electricity.
The rest of the infrastructure - printers, faxes, access points, etc. runs 24/7. Again, the complexity to shut them down would never be equal to the energy savings.
Re:Hibernate (Score:5, Informative)
Re:We have power down at night policy (Score:5, Informative)
Re:We power down at weekends (Score:4, Informative)
Well over half a million dollars if I did the math right.
Surely you could use wake on lan to wake the machines then do your rollout 10 minutes later? Or do a patch install when the machine is turned on and connects to the domain controller?
Unfortunately, this doesn't always work well. On some networks, the machines will auto-start up the moment they receive a packet, even if it isn't intended for them.
Re:Hibernate (Score:3, Informative)
This [mvps.org] was the top result in Google when I searched for "windows remote power down API".
Yes, but not strictly enforced (Score:5, Informative)
Yes and no.
When I first got comfortable in my current job, I made a big push toward "greening" our IT resources. As one obvious (erroneously, as I'll explain in a sec) step in this, I convinced most of my users to shut down at night. If we need to push out updates, WOL works just fine for turning machines on a couple hours before the start of the day, and it doesn't impact anyone during working hours.
Then I learned how electric billing actually works for commercial users - Put simply, your company doesn't care if machines stay on all night, because they pay based on their peak load, which will always occur during normal business hours. I had applied ideas that make perfect sense at home, to an environment where they don't apply.
Now, that doesn't mean we should just leave machines on 24/7 - Using electricity has an an environmental aspect in addition to the monetary cost. But if it inconveniences users by more than a few seconds every day, any conservation efforts will actually cost the company money in the long run.
So, I still encourage my users to shut down, and 95% comply. But if they consider it too much of a hassle, I can't financially justify forcing them to spend the first minute of the work day waiting for their machine to boot (not that anyone really works for the first five to ten minutes of the day, between coffee, hitting the bathroom, and just getting the obligatory morning socializing out of the way).
As for the security aspect of this, the servers must run 24/7, and any attacker would target them rather than some random user's desktop. I don't worry about an attacker using a compromised desktop as an intermediate step to the servers, because the desktops have no more privileges on them than anything else inside the firewall (and even then, not much more than a totally untrusted source, except for nonconfidential shared resources that we could restore in a matter of minutes if necessary).
Re:I used to turn my machine off at night ... (Score:5, Informative)
Me too!
In any cases, I always leave my computer (a laptop) on during the week. I shut it off on weekends, but due to the software inventory tracker and the required anti-virus scans, I always leave the machine on during the week so that I can actually use it during the day.
The real problem is that the anti-virus scan is so slow that it takes a good three hours. The inventory scan is somewhat better, and only takes about an hour. In both cases, the machine drags to near unusable levels while the scan is running. Given that it's a dual-core machine, this is really a testament to just how screwed up Window's I/O scheduling is - both involve lots of file reads, which apparently causes Windows to drag to a crawl.
Not to mention that hibernate and to a lesser degree suspend appear to not work well with certain drivers on my system. Using hibernate kills the wireless drivers, which isn't a horribly big deal when I can physically plug the system in but it does mean that I just shut the thing off when roaming about, since I'll have to reboot anyway.
But it's that three-hour IT required virus scan that keeps me leaving the machine running nights. That's a real productivity killer during the day. Fortunately it's only scheduled to run once a week.
The inventory app, on the other hand, runs daily for some reason.
Overnight tasks (Score:5, Informative)
With many enterprise management tools, such as Zenworks, it's quite simple to schedule a wake-on-lan task to wake computers up at say, 6am, to perform their daily tasks. It can even be configured to push out an automatic reimage of the machine. Once the updates and scans are done by 7am, people are just beginning to come into the office, yet you've still had a whole 10 hours of downtime. Incidentally, I've not seen a single computer in the past 4 years that doesn't support WoL on the mainboard NIC. Big bucks enterprise manglement apps aren't even required. A simple cron job, and some wakelan/ether-wake/wakeonlan/Net::Wake magic will do it for free. Just gather a list of Mac addresses with ettercap or your friendly ARP table or asset management app/spreadsheet.
May will say that the bandwidth requirements of updates squeezed into the 6am to 7am slot will degrade systems, but that's where a background process such as BITS [wikipedia.org] should be used (as demonstrated by Eve Online, Zenworks, Microsoft and Google). The virus updates are a minor bandwidth requirement if you have suitable leaf services, and the actual scan is only locally intensive.
Being a public sector organisation, we're working towards a greener profile (due to govt policies), and all the tools are there and working. It just needs some effort on the part of the administrators.
viruses (Score:5, Informative)
Re:Do you support wake-on-lan? (Score:4, Informative)
I'm going to roll this out to our admin network computers as well. We are really saving noticable amounts of money, because not only are the machines not powered, but the AC doesn't have to run to keep the rooms cooled. THe only glitch I have ran into is when I need to push out updates to all computers, and some were not turned on that day. In the late afternoon, I use WOL to wake up all computers on campus.
Tool to do this The Right Way from the EPA (Score:5, Informative)
Unfortunately the EPA's EZ GPO page seems to have gone poof or something recently, but you can get it here. [terranovum.com]
Basically, you push a (simple) msi to the machines (I do this a lot of the time via psexec [microsoft.com] (props to Mark Russinovich) but there are other methods. Once you have that running on the machine you can configure how you want your machines to behave/re power management:
We also have a script that runs at midnight a few days of the month that does the magic packet thing as has been mentioned so WSUS and/or SMS (or SC:CM) can do their thing and automatic updates run as normal. In a few "why does my machine have to boot up every day this sucks" user groups we have a scheduled job to send magic packets about 15 minutes before they arrive to wake up their machines. With hybernate they hardly know anything happened.
Re:Hibernate (Score:2, Informative)
Might I suggest you set up a web page with wordpress / blogger, document your projects and give prospective employers a way to contact you.
I work for a large company that is always looking for talent. But I cannot give a slashdot post to HR.
Re:The Green fad, is just that... marketing nonsen (Score:5, Informative)
I work for Dell. I can tell you for a fact that we take the environment seriously. The building I work in houses a 24/7 call center, but certain areas of the building are not 24/7. Corporate sales for the country are here, and take up half of the 3rd floor, for example. I happen to be in the sales department myself, and there's a piece of software installed on every desktop that hibernates the computer at 20:30 EST (with a half-hour countdown to that point). My department shuts down at 19:00, no other sales department is open past 20:00. We all open at 08:00 the next day, and the automatic hibernation sets an alarm to wake up the computer at 07:45. Alternately, if you turn your own system off through the start button and shut down, it'll stay off until you turn it back on.
We've also got computer recycling programs in place, and the "plant a tree" initiative where you can have us plant a tree for every computer you buy.
Sure. Some companies don't take going green seriously. But some do. And the number of companies that are taking it seriously is growing. Besides which, every little bit helps. Do you know the amount of energy that could be saved if everybody unplugged those electronic devices that "sleep" when they're not being used? 2W doesn't sound like much, until you multiply it by half a billion devices.
Re:Create job to force automatic reboot or shutdow (Score:5, Informative)
Two simple batch files for XP, on in the All Users startup directory, one in the All Users\Information Services directory of the start menu.
Startup:
AT
AT 18:00 "shutdown -t 600"
Abort:
Shutdown -a
We reset the AT table every day just in case some know-it-all high school student finds out such a thing exists and starts screwing with it. For the most part, though, not even the techs knew such a thing existed until I proposed using it.
We tried a lot of other ideas, but this is the simplest and most user-friendly. Big signs don't work, teachers and lab aids are no better than the students about following directions. Since implementing it 18 months ago, we've gone from having roughly 900 PCs online at night to about 100...including servers, timeclock systems running thinstation terminal sessions, and technology and admin workstations that are excepted from the shutdown policy.
Some scientists need their computers on (Score:3, Informative)
I'm certain there are other sciences that have similar concerns. I think the best way is to send out a friendly e-mail reminding people to turn off their computers when they leave. That should get at least a handful of computers off for the night. Depending on how successful or unsuccessful that strategy is, shutting off computers that are definitely unnecessary (public access terminals for example) would be a fine idea.
Re:Hibernate (Score:3, Informative)
Just remember to stagger start up on the machines, or you might trip a breaker.
Spinning down HDDs is not a good idea, at least on Windows. It tends to spin them back up after 1 minute anyway, causing constant stop/start cycling.
Re:Create job to force automatic reboot or shutdow (Score:3, Informative)
It should be noted that this is a public K-12 school, not a university. There aren't many people around at 6:00 outside of administration personnel. Those who are have been warned what will happen; if they get up at 5:58 to do whatever and come back seven minutes later to their PC shut down, they'd better have saved their work.
Re:Create job to force automatic reboot or shutdow (Score:2, Informative)
Re:Aside from being green... Just let them stay on (Score:5, Informative)
the power station does throttle down at night. they keep the generator at the same speed (3600RPM I guess, to give you 60Hz). but they don't need the same amount of fuel to keep it going. the usage on the grid acts like a brake on the generator, in the same way that the road conditions affect your bicycle.
if it's steam-based (gas, coal, nuclear), you need more steam to keep a higher pressure, to keep the generator rotating at the same speed, and that means heating more water, and more water needs more energy, and more energy needs more fuel. hydroelectric plants shut down unused turbines.
Re:Uh, Sleep Mode - shutdown? (Score:5, Informative)
Re:Uh, Sleep Mode - shutdown? (Score:5, Informative)
Wow! (Score:3, Informative)
No (Score:2, Informative)
The only times this computer goes off is for a few ms when it's rebooting to go into Windows or just rebooting (not very often). Often this computer is in either Windows or Linux for days before another reboot.
However, I do hate when computers are on and are not doing anything at all. My room mate would leave his laptop on all the time doing NOTHING other than being connected to AIM. I guess if he wants to receive messages while he's gone (a modern answering machine). But to me it's entirely useless. I hardly ever receive messages while away (yes I may not be equally social as my room mate, other than IRC all the time).
I guess if I had NOTHING to do with computers then I would not have mine on much, but I do A LOT.
Answer: force them to power down (Score:3, Informative)
Interestingly, our network guys are having trouble routing wake on lan packets accross subnets, so we are looking at a T104 form factor linux appliences with multiple nics to send out WOL commands. Not sure this isn't a brain fart on the part of the network guys, or simply a limitation on how WOL works. Since we have other reasons for wanting a boxen on each network, it's a good excuse.
There's also three other reasons to do it (Score:3, Informative)
Another along those lines is if you want a good power supply, your options are sometimes limited. When I went to get mine I wanted a Corsair supply as I really like their design and build, but 520 and 620 were the only two wattage options. Works out ok, I have a very high power system and a 620 is about double what I need so peak efficiency, but regardless I had little choice if I wanted those kind of supplies.
The final reason is if you instead buy a cheap supply that they are rated improperly. First off they are often rated rather unrealistically. A 500 watt supply will only supply 500 watts if it is very cool, and 500 is the absolute max, the failure point (whereas a good one will supply 500 even at 50+ degrees C and can do so without risking failure). Also they often don't have enough power to given rails to meet you needs. So while they might be 500 watts total, there isn't enough amperage on the 12 volt rails for your system, because a large part of that wattage is for other rails (good ones generally have lots of amperage on all rails, often enough that you can't load all rails fully, but provided some are loaded light you can load other heavy).
Hence lots of people buy overspec'd powersupplies either because they've been screwed on cheap ones, because they want a particular good one that is only available in certain ratings, or both. I mostly just wanted to point out that doesn't mean systems draw that much, especially when idle. Many people see computers being put with 500-1000 watt power supplies and assume that means they draw that much power all the time. That's just not the case. You'll find that a system may have a 500 watt power supply but draw only 200 watts when fully loaded and only about 50 when just idling.
Re:Aside from being green... Just let them stay on (Score:1, Informative)
Seriously?
The parent post was overly simplistic ... but so is yours. Coal-fired plants have these huge boilers, you see, and it is very difficult to adjust the fuel consumption to the peaks and valleys. As a result, these plants do keep spewing out CO2 at night.
Utilities try and work around this with natural-gas fired generators that run only during the peaks, but the fuel for these plants is significantly more expensive, as is the capital cost of sizing the grid for peaks.
The net result of this: there is a lot of electricity available at night. Large businesses pay way more for electricity at peak. Off-peak loads aren't even measured some times.
In short, the parent is closer to being correct ... turning off machines at night will not make that much of a difference. It's a simple economics and engineering fact.
Re:We power down at weekends (Score:1, Informative)
The hard part in this equation is the difference in cost between peak and non-peak. For larger buildings / campuses, it is literally like night and day - often they aren't billed by kwh, but by peak load. It is possible for the cost of that power to be zero.
Re:Aside from being green... (Score:3, Informative)
Wake on LAN requires a magic packet, so browse list refreshes shouldn't be a problem. A PC directly connected to the internet might be wakeable if people send it a WoL packet, and I guess that's a fairly intelligent thing for a network scanner to do if you're looking to infect as many PCs as possible, but would probably be difficult.
From everyone's favourite almost-an-encyclopedia [wikipedia.org]:
It's reasonably unlikely that any random traffic will happen to match this particular pattern. It's possible there's some really crappy chips out there that took "Wake on LAN" to mean "wake if there's any traffic received on the wire whatsoever", but which might make you feel clever in a lab but would be near-useless in the real world.
I thought there were two magic packet standards, but perhaps I'm misremembering things. It might be that the standard port has been changing making several "versions".
Also regarding power, a CPU likely requires other supporting functions to be powered up as well, so while a NIC might not use much more power waiting for a WoL packet than an idle CPU would, you probably also need to factor in memory, maybe video, and probably at least one low speed fan running for the CPU even at idle.