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Powering Down DS25 Alpha Server

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Michelle_68
Frequent Advisor

Powering Down DS25 Alpha Server

Looking for expert opinions and expert advice.
Our customer would like to power down their DS25 Alpha Server at the end of every day to conserve energy. Would this have any adverse affects on any of the equipment on the system such as hard drives, power supplies, etc?

Thanks!!
13 REPLIES
Thomas Ritter
Respected Contributor

Re: Powering Down DS25 Alpha Server

Michelle, by conserving energy do you mean save on electricty costs ? Have they done the sums ?

Powering off and on wont be a problem. Experience shows that hardware failures can occur on power ups. Disk at the end of their life usually go first. Otherwise its no different to switching off a TV.
my AUS 2 cents.
Allan Bowman
Respected Contributor

Re: Powering Down DS25 Alpha Server

As Thomas said, hardware failures sometimes occur during the power-up process. I used to manage approx. 40 MicroVax 3100-85's and most of them were left on 24x7. The few that were only turned on when needed ended up having the most failures - usually the power supply, sometimes a disk drive.

I leave my home PC on all the time except when I will be gone for at least a few days. I have never had a single hardware problem with it - I have had it for over 8 years now, so the hardware is a bit outdated, but it works.

Bottom line is that I would recommend leaving the Alpha on all the time. The only exception would be if it is in an office environment that is not air conditioned at night or on the weekend. You are probably okay if the ambient temperature never gets higher than about 78.

Allan in Atlanta
Steven Schweda
Honored Contributor

Re: Powering Down DS25 Alpha Server

Assuming 500W power consumption and energy
cost of $0.10/kWh, it would appear to eat
about $440/year if left on always. (Add the
cost of heat removal if you didn't need the
space-heater effect.)

I've seen more equipment fail at power-on
than when it was just running along, but most
of the failures were on old stuff, usually
disk drives.

Assuming that the operating environment was
comfy, I'd probably be willing to pay $1/day
to avoid cycling the power. If conditions
were hostile (hot), I'd need to think it
over more.

I don't know of an authoritative analysis of
this question.
Ian Miller.
Honored Contributor
Solution

Re: Powering Down DS25 Alpha Server

I agree with the others. Leave it on. DS25 are not big power users and will run for years. Powering off/on daily introdces unecessary risk.
____________________
Purely Personal Opinion
Karl Rohwedder
Honored Contributor

Re: Powering Down DS25 Alpha Server

I also wanted to save energy and switched my DS10 at home off/on daily. Shortly after that the powersupply died, now it runs around the clock.

regards Kalle
Peter Zeiszler
Trusted Contributor

Re: Powering Down DS25 Alpha Server

We have had systems running for over 5 years. Had one environment that was up for 3+ years until a power hit took us out - drained the UPS. We lost 2 disks when power was restored.

The powersupply and disks will most likely be hit first. Power supply on the power surges as you power up and disks because of mechanical parts. Sometimes fans will also start to go but those are fewer meantime between failures.

If you have a monitor attached you could power that off to save a little. Really makes a difference if you only access the system remotely all of the time.

The majority of the people seem to have the same opinion that you will encounter more hardware failures powering up and down the system. Most of us have experienced that problem too.

If you are also having to cool a room - like maybe its in a small closet. Then you might have to power down for heat reasons. I have had to keep systems in conditions like that and have had systems shutdown because of high temp. I would rather power down than overtemp.

So are your customer wanting to save just for the electrical cost or are there other considerations? Are they powering down their complete network overnight too? (just might get some huge log files if there is no network) Are they powering down air conditioning overnight or over the weekends?
Doug Phillips
Trusted Contributor

Re: Powering Down DS25 Alpha Server

The highest power draw and component stress comes at power-up time. A "quiet" system kept in a proper environment draws only a fraction of its power rating to keep it running but will draw close to its peak rating when it powers up. Inertia.

Consider epsecially the stress and wear to the system caused by constant heating and cooling. If you live in a temperate climate you only need to look at your roadways, walkways and foundation walls each spring to understand this. Or, think about when a lightbulb is most likely to burn out --- mine most often do when I turn on the switch.

Spend the time and/or money to give your systems a good environment and leave them on.

Phillip Thayer
Esteemed Contributor

Re: Powering Down DS25 Alpha Server

Michelle,

I agree with whateveryone else has said. The stress on the hardware happens at power down and power up. More so at power-up than any other time. I would also be willing to bet that the power consumption will actually increase in this scenario because of the high draw on power at power up.

Think of it as a car, Where do you use more gas? When you start from a stop or when your cruising down the highway? You will use more when you start from a stop. Cruising down the road is easy to maintain without using too much gas.

Phil
Once it's in production it's all bugs after that.
Steven Schweda
Honored Contributor

Re: Powering Down DS25 Alpha Server

> I would also be willing to bet that the
> power consumption will actually increase in
> this scenario because of the high draw on
> power at power up.

Well, duh. Yes, the power consumption will
be higher at power-on -- for several
milliseconds. My local electric utility
charges for energy, not power, so who cares?

> Think of it as a car, Where do you use more
> gas? When you start from a stop or when
> your cruising down the highway?

What about my cruising down the highway? Or
did you mean "you're"?

So I should leave the engine running all the
time instead of turning it off when the car's
parked for several hours? That sounds like a
real money saver.
Wim Van den Wyngaert
Honored Contributor

Re: Powering Down DS25 Alpha Server

Over here they do a power cut every 2 weeks and between 10 and 20 Alphastations go off and on again a second later. This for more than 10 years. Not had any problems yet except settings lost due to empty battery. Off course, these stations don't cool off as would your server (1s against a night). I would think that a device that never cools off is more reliable. But I'm not an electrician.

I have seen some disk failures after power off.

BTW : if you use shadowing it is very well possible that you will get a shadow copy if not properly shutdown. And on my systems it seems impossible to avoid completely (so test it).

Wim

Wim
Wim Van den Wyngaert
Honored Contributor

Re: Powering Down DS25 Alpha Server

BTW2 : make sure that your monitoring tools detect things that fail during power on. Many tools use device errors or shadow set changes to detect them.

BTW3 : if a disk or whatever fails you will notice it in the morning at boot time. If running 24/24 you will notice it much sooner (if you have appropriate monitoring) and you can repair it before the business day starts.

BTW4 : what is the cost of doing the manual power off/on, the risk that the person is ill/late, the risk that boot goes wrong, ...

BTW5 : I like the green thought of it ...

Wim
Wim
Thomas Ritter
Respected Contributor

Re: Powering Down DS25 Alpha Server

Michelle, did you find the advise useful ? Worthy of any points ?

Robert Gezelter
Honored Contributor

Re: Powering Down DS25 Alpha Server

Michelle,

I will readily admit that I have not done this experiment on a full basis with the DS25, but once upon a time, I had an equivalent experiment occur naturally with a group of Professional 350 systems.

For many years, a Professional 350 served as my administrative system. As a matter of routine, I left it powered up and running 24x7x366. Failures were infrequent.

A client of mine (a law office, to be precise) had a pair of equivalent systems (all of these systems were originally purchased from the same source). As a matter of course, they powered down their systems at the end of each workday.

Neither of the two offices, which were within one mile of each other, had power conditioning or UPS systems, beyond perhaps an ISOBAR in each location.

The incidence of system hardwware malfunctions was significantly higher for the systems that were power cycled on an ongoing basis.

There is some basis for this. Drastic temperature changes does produce problems of expansion and contraction on components. Power cycling also often produces power surges every time the system is started. If the system is well designed, the impact is less, however cycling is certainly more stress on the system than a continuous state. Electromechanical components are also often responsible for more of the power consumption (and are also often less damaged by power cycling) than are VLSI components.

That said, idle shutoffs for spinning storage, good. Cycling server CPUs, less good. Check where you are actually burning power, it is often worth the effort.

- Bob Gezelter, http://www.rlgsc.com