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When Does Powering Down Servers Make Sense?

timothy posted more than 5 years ago | from the after-coffee-is-served-of-course dept.

Power 301

snydeq writes "Powering down servers to conserve energy is a controversial practice that, if undertaken wisely, could greatly benefit IT in its quest to rein in energy costs in the datacenter. Though power cycling's long-term effects on server hardware may be mythical, its effects on IT and business operations are certainly real and often detrimental. Yet, development, staging, batch processing, failover — several server environments seem like prime candidates for routine power cycling to reduce datacenter energy consumption. Under what conditions and in what environments does powering down servers seem to make the most economic and operational sense, and what tips do folks have to offer to those considering making use of the practice?"

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First Dupe? (-1, Redundant)

I cant believe its n (1103137) | more than 5 years ago | (#25574103)

(See sig)

Only when it makes sense (5, Funny)

Yvan256 (722131) | more than 5 years ago | (#25574105)

Like when someone posts your domain name on slashdot!

You can't take down a server that's already off-line.

Re:Only when it makes sense (5, Funny)

TubeSteak (669689) | more than 5 years ago | (#25575027)

You can't take down a server that's already off-line.

Nuke the entire site from orbit.
It's the only way to be sure.

oh nos (1)

EncryptedSoldier (1278816) | more than 5 years ago | (#25574115)

I have always been afraid to shutdown the servers whenever it is not completely necessary. There are other ways to cut down on costs for most setups. I can't really think of a setup or situation where I would power down servers to save money.

Re:oh nos (0)

Anonymous Coward | more than 5 years ago | (#25574847)

Absolutely. For some people it may be "mythical", but my reality is that the last two times we had a power outage hard drives and power supplies failed. Tape some cardboard over that power button and let it run 'til it dies.

Praise Allah, I finally found it! (-1, Troll)

Anonymous Coward | more than 5 years ago | (#25574125)

I was always looking for something that would fit well in my anus and it seems that Apple has the solution :)

http://store.apple.com/us/product/MB112LL/A?fnode=MTY1NDA1Mg&mco=NzUwOTc [apple.com]

Re:Praise Allah, I finally found it! (-1, Offtopic)

Anonymous Coward | more than 5 years ago | (#25574223)

What?! I mean seriously.... WHAT?! I've seen odd posts on /. but one from a person who would like to shove a mouse up their bum is in a whole new league of /. weirdness. And for what it is worth - careful the plastic casing doesn't fracture!

Re:Praise Allah, I finally found it! (-1, Troll)

Anonymous Coward | more than 5 years ago | (#25574295)

That's what the new MacFags are indoctrinated with.

After they climb through the ranks, they're able to fit this [wikimedia.org] into their anus, as long as they set it with the screen down on the floor and work their way from the back forward.

The MightyPlug, by Apple (-1, Flamebait)

Anonymous Coward | more than 5 years ago | (#25574387)

Apple helps customers screw themselves and it still screws them on the price!

The moment when.... (4, Funny)

TheNecromancer (179644) | more than 5 years ago | (#25574139)

you see the Windows logo appear? (sorry, couldn't resist)

Re:The moment when.... (5, Funny)

Yvan256 (722131) | more than 5 years ago | (#25574251)

Give it 30 seconds and it'll do it on its own (sorry couldn't resist either)

Re:The moment when.... (1)

db32 (862117) | more than 5 years ago | (#25574425)

How do I metamoderate this being moderated as +Informative as +Funny?

Simple (5, Funny)

eln (21727) | more than 5 years ago | (#25574153)

The best time to shut down the servers is right before you quit your job. Password-protecting the BIOS first adds value too.

WOL (5, Insightful)

Anonymous Coward | more than 5 years ago | (#25574157)

Put redundant/failover servers into a sleep state and enable WOL.

Business needs and Risk (4, Insightful)

Kamokazi (1080091) | more than 5 years ago | (#25574161)

It's pretty much up to your business....what must run 24/7, what systems are likely to get accessed in off hours, and how likely is that, and how critical are they? With redundant systems, can there be any downtime while they are powered up, or should it be immediate failover? If you use virtualization the redundancy should be easier to manage in many cases...you may be able to immediately offload to running systems and power up backup systems and then bring the VMs up there.

It's hard to get very specific without knowing your business and what you are running and what the needs are.

Re:Business needs and Risk (2, Interesting)

LWATCDR (28044) | more than 5 years ago | (#25574395)

Your correct.
A lot of places I know shut completely down at night but leave the servers up and running. Often it is so they can run end of night jobs or just so they can get up and running quickly in the morning.
A lot of it is just waste and a lot of it is just habit.
Now for people that run 24/7? That is totaly up to you.

Re:Business needs and Risk (1)

LandDolphin (1202876) | more than 5 years ago | (#25575079)

Seems a lot of places don't really worry about their power consumption. Look at how many places leave the lights on all night.

Re:Business needs and Risk (5, Interesting)

vwjeff (709903) | more than 5 years ago | (#25574761)

Example Setup The organization I work for has a well known usage patterns that we use to make decisions like this. 95% or more of our traffic occurs during business hours which we define as 7:00 AM - 7:00 PM. During business hours we have dedicated servers for various functions. We have a cluster of servers running virtual server instances that duplicate the dedicated servers. During off hours the dedicated servers are powered down and the virtual server instances take over. It works for us and we have seen a significant decrease in power usage with no impact on our users.

I go by a few simple rules... (5, Funny)

Anonymous Coward | more than 5 years ago | (#25574163)

I'm glad this was posted to "Ask Slashdot" where your audience is highly seasoned professionals that can give you wise, insightful answers...
In the data center that I manage, I use a few simple rules to determine when I power them down.
1) If the server is on fire
2) If there are no users using the server
or
3) If the power company is saying that I haven't paid my bill and they are sending "Hank" over to cut me off
4) Civil unrest, tornado, earthquake, zombies, etc.

Re:I go by a few simple rules... (5, Funny)

Anonymous Coward | more than 5 years ago | (#25574661)

I'm glad this was posted to "Ask Slashdot" where your audience is highly seasoned professionals that can give you wise, insightful answers...
In the data center that I manage, I use a few simple rules to determine when I power them down.
1) If the server is on fire
2) If there are no users using the server
or
3) If the power company is saying that I haven't paid my bill and they are sending "Hank" over to cut me off
4) Civil unrest, tornado, earthquake, zombies, etc.

Zombies aren't a good reason for shutting down the servers, that's why our IT guy keeps a shotgun leaned up against the server....at least he says it's for zombies.

Virtualize! Virtualize! Virtualize! (5, Interesting)

Anonymous Coward | more than 5 years ago | (#25574187)

If you virtualized your servers, you could create a managed power-down/power-up scenario. In the morning, your servers would turn on, your virtualized instances would move around (so they have more power for the day's activities), and then at night they'd retreat to a smaller group of servers. The unused servers could shut down for the night. You could even rotate which servers stay on overnight keeping the virtual servers running to spread the wear around if there is some.

Re:Virtualize! Virtualize! Virtualize! (5, Informative)

Amarok.Org (514102) | more than 5 years ago | (#25574417)

There are a number of tools and products out there to assist this.

Consider a large (65k+ employees) company that has a several hundred server implementation that they use to process payroll every two weeks. They use a management tool to power them up on Friday, process payroll over the weekend, and shut them down on Monday. The power and cooling cost impact of these several hundred servers *not* running most of the month (6 or so days a month instead of 31) is huge.

Another (and also in use by the same company) strategy is to virtualize the OS instances, spin those up and down as necessary, and then use something like VMWare's VMotion to maximize usage of the physical boxes - and again use another tool to power down unneeded compute capacity.

Welcome to the virtual world...

Lots of prerequisites, but when it works, it's pretty freakin' sweet...

Re:Virtualize! Virtualize! Virtualize! (-1, Redundant)

Anonymous Coward | more than 5 years ago | (#25574575)

*Slams foot in parent's ass*

Sorry, developer's knee jerk.

Re:Virtualize! Virtualize! Virtualize! (0)

Anonymous Coward | more than 5 years ago | (#25574641)

Uh... what?

Re:Virtualize! Virtualize! Virtualize! (4, Informative)

agallagh42 (301559) | more than 5 years ago | (#25574635)

...and again use another tool to power down unneeded compute capacity.

And that other tool is ... VMware! DPM (distributed power management) is built right in, and does exactly what you describe.

http://www.vmware.com/products/vi/vc/drs.html [vmware.com] (scroll to the bottom)

Welcome to the virtual world...

Yup, the game is officially changed.

Re:Virtualize! Virtualize! Virtualize! (4, Informative)

Amarok.Org (514102) | more than 5 years ago | (#25574849)

Actually, the other tool in this case is Cisco's VFrame Data Center. The problem with DPM (and other VMware tools) is that they won't let you move a physical box between ESX clusters. If you have multiple ESX clusters, the physical machine stays with it - powered up or not. With VFrame, the system can be powered down, removed from the cluster, and added to another if/when necessary... including any necessary network configuration (VLAN memberships, etc) and SAN configuration (zoning changes, LUN masking).

Not that I'm complaining about VMWare's solution to this problem - they're actually quite complimentary.

Re:Virtualize! Virtualize! Virtualize! (1)

bluesk1d (982728) | more than 5 years ago | (#25574795)

Vmotion ftw!

Old news (0)

Anonymous Coward | more than 5 years ago | (#25574209)

I thought we had this discussion last week.

Well... (1)

Drakin020 (980931) | more than 5 years ago | (#25574215)

Does it make much of a difference if all your servers plug into a rack mount UPS that draws the same amount of power regardless of the devices running?

Re:Well... (5, Insightful)

csnydermvpsoft (596111) | more than 5 years ago | (#25574287)

What kind of UPS does that? If the batteries are already charged, what would it be doing with the power that's not consumed by the devices - does it also act as a space-heater?

The ratings for UPS's - and any other power supply - are peak loads, if the UPS is being used at 100% capacity.

Re:Well... (1)

multipartmixed (163409) | more than 5 years ago | (#25574815)

Man, I gotta get me one of those UPSes!

Preferably one that only draws 2-3 VA.

Then I could plug all my servers into it, and save a BOATLOAD of money!

(My datacenter charges about a buck a VA)

Like a car... (4, Interesting)

fiftysixquarters (1078091) | more than 5 years ago | (#25574217)

Seriously, this analogy makes sense. When a car is cruising on the high way it's able to maintain speed using 4/8 cylinders. Servers could be cycled in a similar fashion. Do you really need 20 web servers running at 3 am on a Sunday?

Re:Like a car... (2, Insightful)

Yvan256 (722131) | more than 5 years ago | (#25574263)

It's not 03:00 everywhere on the planet nor is it sunday either.

Re:Like a car... (2, Insightful)

hesiod (111176) | more than 5 years ago | (#25574361)

You're assuming the web servers are for an international service.

Re:Like a car... (4, Insightful)

Yvan256 (722131) | more than 5 years ago | (#25574397)

If it's a website, it's international, wether or not the actual products and services are available internationally.

Re:Like a car... (0)

Anonymous Coward | more than 5 years ago | (#25574509)

Except there are a lot of places that use internal websites.

Re:Like a car... (2, Insightful)

hesiod (111176) | more than 5 years ago | (#25574535)

He didn't say website, he said "web servers" which, despite the name "web", could serve an internal web-based service to a large company that only exists in one region of the world.

Re:Like a car... (1)

cbreaker (561297) | more than 5 years ago | (#25574669)

Sure, but that's just trying to rationalize a dumb argument that every web site is used all over the world, and that's simply not true. English speaking sites usually only get hit from the North America and the UK regions.

I guess now we're both feeding the troll.

Re:Like a car... (1)

Nos. (179609) | more than 5 years ago | (#25574621)

Yes but if your site has a mostly domestic user base, then you probably don't need all 20 running. As others have said, using virtual machines, you could probably have most of the physical ones shut down, but brought back automatically as the load increases.

Re:Like a car... (1)

xaxa (988988) | more than 5 years ago | (#25574749)

If the website is served by more than one computer then it might make sense to turn some off when the target market is asleep.

I bet most American store websites get most of their traffic when America is awake.

Re:Like a car... (3, Insightful)

compro01 (777531) | more than 5 years ago | (#25574413)

Excepting google and such, I doubt that the vast majority of servers would have such a geographically balanced workload.

Re:Like a car... (2, Insightful)

mmkkbb (816035) | more than 5 years ago | (#25574467)

Google likely shunts load to different datacenters based on location.

Re:Like a car... (2, Insightful)

DragonWriter (970822) | more than 5 years ago | (#25574555)

It's not 03:00 everywhere on the planet nor is it sunday either.

Its quite likely that, even if your server is serving the public over the internet (which is certainly not the case for all servers), the userbase isn't spread uniformly across all available timezones.

Re:Like a car... (1)

fiftysixquarters (1078091) | more than 5 years ago | (#25574645)

Excellent point. Didn't really think that through.

Re:Like a car... (1)

Amarok.Org (514102) | more than 5 years ago | (#25574929)

No, but lots of services (not just Web services) have peak times... the problem is, with traditional architecture, you have to size/plan for peak load - and much of that capacity sits idle waiting for the peak.

With various solutions out there (discussed in other posts already), you can power down unneeded capacity (or repurpose it) during the down times, and bring it online when necessary.

No, you're not going to do this with your big ERP application or whatever... but for web farms, compute clusters, app clusters, etc... it makes a lot of sense.

Re:Like a car... (1)

Etrias (1121031) | more than 5 years ago | (#25574679)

Oh thank God. I hadn't seen a car analogy in the last couple of articles and was beginning to wonder if I was on the right site.

Slashdot? You're soaking in it!

Do you have any idea... (1)

csoto (220540) | more than 5 years ago | (#25574779)

...just how much pr0n gets done at 3a.m. on Sunday? Really, man!

Re:Like a car... (1)

genner (694963) | more than 5 years ago | (#25574971)

Seriously, this analogy makes sense. When a car is cruising on the high way it's able to maintain speed using 4/8 cylinders. Servers could be cycled in a similar fashion. Do you really need 20 web servers running at 3 am on a Sunday?

So it's like putting to much air in a balloon and something bad happens....?

When.. (2, Insightful)

geekymachoman (1261484) | more than 5 years ago | (#25574219)

.. your business doesn't depend on it.

Seriously .. powering down failover boxes or something like that is not wise thing to do.

Imagine in some fucked up situation, when your main systems goes down... you can't boot failover servers for some reason ... long fsck, or whatever.

You can power off the servers that aren't critical .. Why question on slashdot for that ?

Logic anyone ?

I suppose, hypothetically... (0)

Anonymous Coward | more than 5 years ago | (#25574227)

Makes sense to me, if your business hours of operation are 7am-6pm, to leave the servers to do their regular daily maintenance from 7pm-9pm, Monday-Saturday. Then, go to a power-saving status from 9pm-5am, rinse-repeat daily. Heck, even leave this for a 7-day schedule so you can do patches and other non-automated maintenance on Sunday.

Server downtime (1)

EagleRock (973742) | more than 5 years ago | (#25574229)

I know it's the accepted belief in the industry that rebooting servers/downtime can be bad to a server, but couldn't you spin that the other way around and say that running a server 24/7 is bad too? Couldn't there also be benefits from letting a server rest as well?

Best time to shut down servers... (1)

FF8Jake (929704) | more than 5 years ago | (#25574231)

Obviously, the best time to shut them down is when they are running a Windows Server OS of any type. Also it saves you money on chairs and sheetrock repair fees.

Why not use spin down and Cool'n'Quiet / SpeedStep (1)

Joe The Dragon (967727) | more than 5 years ago | (#25574235)

Tech so the system can drop to a low power mode.

Also get rid of the AC to DC and then back AC then back to DC part and only have 1 AC to DC step.

Simple Answer (4, Insightful)

jcnnghm (538570) | more than 5 years ago | (#25574237)

When you're sure you don't need it to come back up.

Not often (4, Insightful)

nine-times (778537) | more than 5 years ago | (#25574239)

How many of us have servers that don't need to be live? Yeah, I guess there might be a development server, but that assumes that you're not developing. There could be a failover server that does nothing when the primary hasn't failed, but in that case you'd want to be damn sure that the failover will come online without difficulty when it needs to.

It seems to me like it would be a pretty rare case when this is applicable. I'd sooner be interested in asking, can they build servers that can selectively power down subsystems that aren't currently in use, sufficiently enough that there's no serious harm. For example, I'd consider putting some of my fileservers' hard drives to sleep over night, but I'd still want the server to be available and the drives to spin back up if I log in from home and need access.

Mostly, I'd say that if you have servers that you don't need to be live, you might not be using your servers efficiently. It may be worth looking into setting up some kind of VM server with various images that can be brought up on command. But hey, if you do have a server that you can turn off without causing problems, go for it.

Re:Not often (3, Interesting)

CFTM (513264) | more than 5 years ago | (#25574305)

Uh I am the administrator of a server that archives all email for our company. We no longer use this solution for our email archiving, but according to federal regulations this email needs to be accessible for at least another 26 months. The only people who use the server anymore are the various alphabet soups of regulators who came in twice a year, maybe I'm the exception but not the rule but I can't see a reason to keep the server on...

Re:Not often (1)

idontgno (624372) | more than 5 years ago | (#25574559)

Um...

You're using an entire server, complete with associated on-line magnetic storage, as a glorified floppy disk?

Wow.

Back that stuff up to tape or permanent optical media and decommision that junk.

I suppose someone proposed that, and got shot down as being too effort-intensive (compared to just letting the server sit).

Seems kinda sad to me.

Re:Not often (1)

CFTM (513264) | more than 5 years ago | (#25574683)

It's on permanent optical media, the databases that make all the data intelligible are stored on the servers. Otherwise you have seven years of email in text files, organized chronologically with absolutely no auditing information attached. Much more efficient systems to do this today, but it was implemented back like '99-'00 and I've inherited it from multiple other admins...good times!

Re:Not often (1)

Splab (574204) | more than 5 years ago | (#25574697)

Actually when you got a hot fail over why not use it for some load balancing?

And the solution is to use virtual servers, some of them support packing down a server and moving it to another physical server - that way you can power down half or more of your physical hardware but still keep all "servers" online. (Provided the systems aren't doing much at night)

Re:Not often (0)

Anonymous Coward | more than 5 years ago | (#25574801)

Who needs a fricking SERVER for developing? Just use a workstation for christ's sake.

Re:Not often (1)

beaviz (314065) | more than 5 years ago | (#25575081)

How many of us have servers that don't need to be live?

Probably not many, but some has - and it's a very real problem. Say you have 50 webservers to sustain load in the afternoon, but 40 of them is just sitting idle at night. Wouldn't it be nice to simply power most of those down?

(DB servers are somewhat more complicated because they need to be in synchronized before use)

When they're not being used (2, Interesting)

Errtu76 (776778) | more than 5 years ago | (#25574241)

Why have 16 terminal servers (sorry, couldn't think of anything else) running when no more than 10-20 users are on it after working hours? Then in the morning, power them back on again using WakeOnLan.

And that backup server with a whole lot of disks? Why not only have it running during the night when stuff is being backed up?

Old gear (0)

Anonymous Coward | more than 5 years ago | (#25574259)

In the last two office moves, I lost three old servers (10+ years). I have a gut feeling that this was due to powering them down, then up. They had been up for several years without any problems. I moved them myself so I know they didn't get banged up.

Long story short, I have servers that I am afraid to power down (but too lazy to do anything but make sure they are backed up regularly)

Re:Old gear (4, Interesting)

xaxa (988988) | more than 5 years ago | (#25574851)

Analogy (this time, light bulbs).
- Light bulbs fail just as you turn them on. Or off.
- They hardly ever fail whilst switched on.

I think servers are the same. You're in trouble if a server you've had switched on for two years and forgotten about loses power and doesn't come back up. If it'd been switched off every weekend it would have failed earlier -- but probably at a more convenient time.

Failover? Are they serious? (1)

bigstrat2003 (1058574) | more than 5 years ago | (#25574271)

Er... yeah, let's power down our backup servers that are there as a safety net. What could possibly go wrong?

I guess these guys don't care about little things like uptime, then?

Power Management (3, Interesting)

Super_Z (756391) | more than 5 years ago | (#25574275)

Powering down your servers tends to introduce response issues. :-)
Some servers, like the HP ProLiant line, has power management features [hp.com] . Try experimenting with features like these first.

Virtualization solves that (2, Insightful)

Ngarrang (1023425) | more than 5 years ago | (#25574289)

"Servers that sit in idle state for long periods of time are the top candidates for powering down between uses."

Then virtualize it or combine its function with another server. I see this part of the article as a bad example. It starts by saying that virtualization has helped, and then uses an example that virtualization would solve, NOT power-cycling.

Maybe its just me, but when I think of a server, I think of something important that is running, that needs to be accessible on something other than a glorified desktop. If it is important, then it cannot be turned off.

Re:Virtualization solves that (1)

pseudonomous (1389971) | more than 5 years ago | (#25574545)

This is really a matter of scale, isn't it? If a small company has, say, 2 servers, one primary, one backup, uses them intensely during business hours, then not at all after hours, what's the point of having those servers still run? How's virtualization supposed to help? Even if you had a bunch of servers, consolidated them through virtualization, in the situation where these machines are primarily serving databases, files, and/or applications that are only in use during business hours, won't these things still sit idle after hours? In this case, Virtualizition DOES help WITHOUT solving the problem. Or at least that's how it seems to me, I've never really worked with a network more complex then the first case, so I could certainly be saying something stupid.

Re:Virtualization solves that (0)

Anonymous Coward | more than 5 years ago | (#25574659)

Maybe its just me, but when I think of a server, I think of something important that is running, that needs to be accessible on something other than a glorified desktop. If it is important, then it cannot be turned off.

It's probably just you. There are tons of servers that are accessed only be some closed user group, the members of which may ven be able to learn that they need to trigger a Wake-On-Lan and wait a few minutes if they want to use it in the middle of the night or on the weekend. Development, test and build-servers are a good example, but believe it or not, I'm running a loadbalanced cluster of 2 servers for one customer where the web-service is actually only available from 8:00-22:00, and just shows a really simple webpage in the "off" hours that the loadbalancers could just as well deliver themselves.

do some analysis (0)

Anonymous Coward | more than 5 years ago | (#25574297)

question: when does sleeping makes sense for you?
answer: when you're tired, not busy, and a short nap wouldn't help.

In other words, if in your datacenter the servers load goes from 100 to 10000 users in minutes, no matter if it's during day or night time, you simply don't put them to sleep or you would actually lose energy and horsepower, then money.
If OTOH you have predictable hours when the systems are underloaded, you could define some rules to turn on unused servers and move some load to them (connections, virtual machines, etc).
Be careful to provide some form of hysteresis [wikipedia.org] or you end up with a system that spends its whole time turning on and off stuff with nasty (expensive, potentially destructive) consequencies.

XenServer (4, Interesting)

Obsession12 (554132) | more than 5 years ago | (#25574347)

Full disclosure, I work for Citrix. Check out XenServer, which can remotely provision server workloads to virtual and bare metal machines - based on load, you can remotely power up resources as needed. I have seen the future, and it is awesome. And green.

Re:XenServer (1)

Creepy Crawler (680178) | more than 5 years ago | (#25574647)

No amount of software can 'fix' a server in which the power supply refuses to turn on.

That's a hardware problem. Seems it would indicate that 12v rails would be the way to go in the datacenter.

Is this a trick question? (0)

fahrbot-bot (874524) | more than 5 years ago | (#25574355)

When Does Powering Down Servers Make Sense?

Umm... Whenever you want them off?

haha (0, Troll)

kingsteve612 (1241114) | more than 5 years ago | (#25574363)

lol@ powering down servers to save energy. alright, heres a situation. youre the net admin at whatever company. do you sleep there? probably not. are you going to leave work at 5pm, come back at midnight to shut your server down? hell no. if yes, are you going to go back at 5am to power them back up? probably... point is, no network admin is going to take the time to power the server off, just to have to power it back on when he/she gets to work. and chances are, if youre not me(has to open the building every morning at 630am) youre probably just going to leave the shit running. stupid question whoever came up with it. Good job at being an idiot. "whens a good time to shut down your servers?"...wow

Re:haha (0)

Anonymous Coward | more than 5 years ago | (#25575033)

Right, because none of this stuff can be automated...

Moron.

Wrong way round (4, Insightful)

symes (835608) | more than 5 years ago | (#25574399)

My guess is that managing energy consumption by powering down servers is the wrong way round - there seems to be a fair bit of interest in developing hardware that manages it's own energy consumption without loss, either in additional power to bring it back up to speed or in processing lag, etc. Of course, this doesn't address the poster's immediate concerns to which I have little to add other than it's probably good to cost in heightened risks of hardware failure and therefore the costs of unscheduled downtime.

Considerations (1)

postbigbang (761081) | more than 5 years ago | (#25574403)

If you're looking to save power, try using cpufreq on Linux, or power settings in Windows Server instead. If you simply shutdown everything by building policy, then have chron or schedular sync the file systems, then do a shut down at the chosen hour, then power them up ten minutes before the start of day (unless you have backups, reports, etc. to run

If the power cost doesn't make any difference, power them down 2x per quarter to blow the dust and crap out of them. Then keep them on if you're already green. Otherwise, power cycling is somewhat traumatic and in my belief shortens the life of disk drives more than anything else, then power supplies. Just my 2c.

right in the middle (2, Funny)

Anonymous Coward | more than 5 years ago | (#25574451)

Right in the middle of a user having completed all of the form and about to hit submit button. Boy, I'd like to see the face of that user!

Geezus Fuck NO! (1)

topham (32406) | more than 5 years ago | (#25574455)

While there may be machines which do not need to be running they should not be refered to as servers in the traditional sense.

More hardware failures occur between powering down, and finishing booting than you can shake a stick at.

Some criteria (3, Informative)

Colin Smith (2679) | more than 5 years ago | (#25574457)

1: Can your service be load balanced across several identical servers?
2: Does your services experience predictable but varying load?
3: Can the state used by your service be rapidly replicated (10 minutes) across newly booted systems?

Not all server systems make good candidates for shutdown. Web farms do tend to because they fit the criteria above.

 

Seconding the virtualize mantra with a twist (1)

TheLoneGundam (615596) | more than 5 years ago | (#25574465)

Try virtualizing your *nix boxen on z/VM, on a z/10 mainframe - especially if your business/organization already has a mainframe. z/Linux is just Linux, after all... Apache and Mono are already ported, among many many other things; what's not ported can be ported in the usual way. The advantage is that you can run virtual servers on the same hardware as your mainframe "legacy" apps, without drastically increasing power consumption.

PSU failures (4, Informative)

blind biker (1066130) | more than 5 years ago | (#25574477)

The problem is the PSU, which fails most often during power-up. Leaving the servers always on has the advantage of avoiding that particular failure mode. Also, other components in the server are prone to failure during power-up, way more often than at steady state. So, powering up your computers is overall a risky moment.

VMWare already does this (1)

jherekc (460597) | more than 5 years ago | (#25574485)

VMWare Virtual Infrastructure can already turn off unneeded physical servers and power them on again when the extra capacity is needed. All the VMs (your actual server that run websites etc.) keep on running, but if they aren't using much CPU/RAM then you can squash them into fewer physical servers (automagically) and power off the unneeded hosts.

I'm no server technician (1)

moniker127 (1290002) | more than 5 years ago | (#25574493)

but wouldn't it make sense, if you have say, 10 servers, to keep 9 of them on and 1 off at all times, doing maintainance on the one that is off, and constantly rotating that?

I'm no server technician either (1)

wjh31 (1372867) | more than 5 years ago | (#25574609)

but for something to spend 10% of its time under maintainance probably means you're doing it wrong

and surely its better to find a save money by reducing cooling costs rather than shutting down servers, or if youve got spare capacity why not rent it out to someone who doesnt what to have to look after a server themselves to justify it being on

STR5 (suspend to ram) (1)

fast turtle (1118037) | more than 5 years ago | (#25574523)

Something interesting is that most PSU's do not completely depower the system due to Wake on Lan/Ring/Timer settings. Due to this, why in hell don't you configure your servers to use STR5 when they're in standby?

If you use static caching or an SSD, you can have the system picking up excess load almost instantly yet while it's sleeping, it's not using anymore power then a system that's off.

The real problem (2, Interesting)

Anonymous Coward | more than 5 years ago | (#25574531)

The real problem with powering down servers is that you won't know there's a problem until you power them up again. The result is that the problem always occur when you need the servers (otherwise you wouldn't be turning them on). This instead of the problem mostly occurring when the servers are not in use or at least not all servers at the same time.

If you power up 1000 servers in approximately 15 minutes (once per day) and 10 don't power up, then you have 10 problems to solve asap. If you don't power up 1000 servers but they also fail approximately 10 per day then you don't have 10 non-working servers at the same time, but randomly distributed over the day. Meaning the problems don't queue up.

VMWare can be used for this (2, Informative)

CPE1704TKS (995414) | more than 5 years ago | (#25574541)

VMWare has some cool functionality such that if you virtualize all your machines, at night time when the loads are lower, you can consolidate all your VMs onto a smaller number of physical machines, and automatically turn off the physical machines. Then, in the morning, as the loads increase, you can automatically power on the physical machines and move the VMs back onto these physical servers to handle the load. Not sure what it's called but when I heard about it, I thought it was really cool.

Wake on LAN? (1)

mpapet (761907) | more than 5 years ago | (#25574577)

It seems to me this is available in *some* hardware. Maybe the parent wants to check into that?

I've got racks of Compaq DL380's and I don't even know if they have Wake on LAN, but they've got other features that do the same thing.

In my environment, service response time is the primary performance metric, saving money by limiting power consumption is viewed as counter productive.

colo (3, Insightful)

donnyspi (701349) | more than 5 years ago | (#25574601)

As long as power use is built into the fixed price I pay for the cabinet I rent at the colo, I'll never turn off my servers if I don't need to. Why would I?

Re:colo (0, Troll)

Anonymous Coward | more than 5 years ago | (#25574837)

Because you want to save the planet?

Tag says it all: virtualization. (1)

DamnStupidElf (649844) | more than 5 years ago | (#25574767)

Once servers are virtualized it becomes trivial to run only the number of virtual servers necessary to handle the load. Cloud computing, in essence. A truly distributed model of computing would work just as well, but my guess is that will only arrive sometime after most servers are already virtualized.

The only impact shutdown and startup should have is on hard disks; all other electronics should take millions of power cycles without any problems as long as the power supplies are gentle. Hard disks for virtual servers would generally live in a SAN anyway, and powering down sections of the SAN would be possible. Some drives already support a low RPM standby mode that lowers power consumption without the danger of cold startups that wear out the spindle motor. And really, shutting hard drives down completely at night and starting them up in the morning would put less load on them than most laptop drives, which already last a couple years at least in a much worse physical environment.

During Long Power Outages (1)

Adeptus_Luminati (634274) | more than 5 years ago | (#25574773)

Powering down non-critical servers make sense:

If a large and potentially long lasting Hydro power outage occurs, and your Data Centre UPS switched over to using your generator, and you want to conserve Diesel / length of uptime your generator can keep the DC up for.

Adeptus

Powered Down = Not a Server (1)

BobMcD (601576) | more than 5 years ago | (#25574863)

This question is a bit of a non-starter. If you can power it down, and no one screams, then it really isn't a 'server' at all. A server serves things and brings with it a promise of availability. If you're not providing the availability, then you really only talking about some other kind of computer, not a 'server' at all.

Turn them off? No. (1)

HuckleCom (690630) | more than 5 years ago | (#25574875)

With the countless geeks with their *nix boxen running 24-7 at home for their unabashed uptime competition with themselves - I think datacenters are pretty efficient considering their purpose and great lengths they go for critical support.

I think there's bigger fish to fry, like the great idea of changing daylight savings time, which in the end didn't save us any energy but sure as hell cost the IT industry a pocket's worth!

P.s.: I turned off my spare 24" Dell display just for a good conscience for the last 3 minutes, there I did my part for the year....

Recently been through three powerdowns (1)

KingDaveRa (620784) | more than 5 years ago | (#25574897)

We recently had to power down our main data centre, three times in fairly quick succession due to major power work that had to be carried out (no building UPS or generator unfortunately... boo!). Doing it was all well and good, but so many things are inter-connected, we found we almost had circular dependencies of things, so we had to be very careful in shutting down and bringing back services. The end result was something different every time wouldn't shut down, and something different every time wouldn't come back right, causing downtime to users. In testing and development it's never an issue when you're bringing something new up. It's when - six months down the line - you've integrated it into everything that you're really into a tangled web of systems, and taking it all down results in much hilarity. We were shutting down 90-odd servers; Windows, Linux, Solaris, FreeBSD, and various other things like Cisco CallManager and other random network kit. It's NOT something I'd want to do again, and having it all scripted would scare the crap out of me quite frankly. It'd require so much testing and checking, you'd be bringing things up and down all the time and causing more trouble than just keeping it up. Try and save the power elsewhere - raise the A/C temp, or virtualise some stuff.

VMware lends itself best to power downs (0)

Anonymous Coward | more than 5 years ago | (#25575047)

So many of the comments are assuming that the server's specific identity is tied to a function.

In a large VMware environment that leverages shared storage, any server can run any virtual machine.

If there are a number of standby servers that can assume additional load, the failure of one of them on startup only affects total resources available but not virtual machines or services.

From someone who's been there... (1, Informative)

Anonymous Coward | more than 5 years ago | (#25575071)

We took our server estate down by a factor of 20 using modern virtualization hardware appliances and hypervisors [xen.org] . Thats right not 10x fewer servers, but 20x. With the right combination of investment in quality shared storage, dedicated virtualization appliances [360is.com] , and the skills to make them work, today our cooling, power, and rack space bills arent worth worrying about.

We are rarely at the cutting edge of technology, but if we can do it, you can.

eliminating temp stress (1)

wikinerd (809585) | more than 5 years ago | (#25575077)

Perhaps we could invent a way to power down servers in a manner that would not cause sudden temperature changes? What about cooling the server while it's on, then warm it while it shuts down, then let it cool gradually again, and then start warming it before we go to switch it on again, and only switch on when it is already warmed? Maybe we could think of a way to keep every chip and every component in a stable temperature and only allow very gradual temp changes. Then temperature change stress would be eliminated.
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