On 11/27/22 12:10, James Johnson wrote:
> Thanks for your response.
>
> I am not intending to switch the machine. In terms of resources, I am
> mainly concerned about hard drives and cpu being worn down
> unnecessarily. I am not sure how much of a concern this should be
> though.
The CPU isn't going to "wear out" due to being running, at least not in
a meaningful time scale.
HISTORICAL EVIDENCE hints that a spinning drive will last longer than
a frequently power cycled drive.
Steady-state is easiest on hw. Powering up and down is large power
surges, and that's generally not good. This is across the board --
power supply, hard drives, main board, CPU, memory, etc. The only
part that I think gets a benefit from being turned off would be a CRT
monitor, and maybe the HV in an older LCD monitor.
That's based on historical experience with a lot of different machines.
How that relates to the hardware you have at hand, there's no way to
know, other than get 50 identical machines, power one half on-and-off
regularly and leave the other half on.
> Yes, I do know in advance when the machine needs to run and when it
> can sleep.
>
> "Some machines have a wake option in their BIOS." -> thanks for the
> pointer, I will look into that.
That might work for you, but I think your premise is flawed.
> "How much electricity have you saved by that?" -> I don't know. The
> main concern is not using the hardware unnecessarily, to hopefully
> increase its lifetime. Though less electricity usage is a nice side
> bonus.
I just did some measurements here before seeing these replies. Short
version: single 4TB 3.5" 5400 RPM drive draws less than 7W when
running...and I doubt you get all that power "back" when you spin
down the drive. CPUs mostly draw power when doing something, the
difference between an mostly idle CPU running at 1GHz vs. 3GHz is
fairly small. And on a rack mount server, fans may draw more power
than an idle CPU.
> "How much resources would that save?" -> My thoughts was that it
> would be better for hard drive longevity to have them spun down,
> rather than them being up for months without any access needed. I
> don't know in practice if that matters for life expectancy of the
> drive?
As someone who has seen a lot of hard drives power down working and
not spin back up at next power-on...I'm pretty sure your plan is
absolutely defeating your goal. I'm pretty sure a whole lot of
other people are also screaming "NO!!!" at their computer right now.
I hold a lot of unpopular views based on my experience, but I'm pretty
sure "leave drives running for maximum life" is NOT one of them,
it's pretty mainstream.
From your elaboration on your goals, just leave it alone. By trying
to make it a super-efficient system, you are going to increase your
downtime and failure in a number of ways.
Nick.
>
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>> On 27 Nov 2022, at 15:50, Jan Stary <hans@stare.cz> wrote:
>>
>> On Nov 27 09:37:19, mytraddress@gmail.com wrote:
>>> The main thing I am trying to do is to make it sleep every now
>>> and then to protect resources.
>>
>> How much eletricity does the machine eat? (What other "resources"
>> are you concerned about?)
>>
>>> 1) Make it sleep and wake up when woken up remotely I
>>> investigated Wake On Lan, which I enabled via ifconfig. However,
>>> this system is deployed remotely, and I have no access to other
>>> computers on the LAN, so I am unable to make this work.
>>>
>>> 2) Make it sleep for a few hours and then wake up
>>
>> Do you know in advance at what hours the machine needs to run, and
>> when it can sleep?
>>
>>> After 3hours+ of research in man pages and the internet, I have
>>> not seen any solution for that.
>>
>> Some machines have a wake option in their BIOS.
>>
>>> 3) hard drives Spin down, CPU lower freq I have been able to
>>> lower the CPU speed by running `apm -L`.
>>
>> How much electricity have you saved by that?
>>
>>> I haven't been able to spin down the hard drives.
>>
>> How much resources would that save?
>>
>> I you are concerned about resources, wouldn't you be better off
>> getting a low-power machine, with SSD disks? There are machines
>> out there that eat around 10W and get the job done (dependeing on
>> the job of course); and SSD doesn't need to spin down.
>>
>>> I cannot share the full dmesg for security reasons
>>
>> Bullshit.
>>
>
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