All this complexity to save a few bucks per year on your electricity bill? This is ridiculous, the Pi costs far more than what you can be expected to save.

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neilv 2 days ago | parent | next [-]

I think it turned out a lot more complicated than the author expected, but that their solution they kindly wrote up will be pragmatic for someone.

(For example, imagine a big home GPU server that is needed only intermittently, and you want it to spin up automatically on network traffic from family's various devices that you can't modify.)

Of course, if you have simpler needs, and you're willing to send a WOL magic packet from the using devices, you can do in a few lines of shell script. It's a 1-line ssh-to-something-that-can-etherwake-on-that-vlan script, then wait in a loop for the service you need to appear, then 1-line ssh-to-server-to-shutdown when you're done.

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daymanstep 2 days ago | parent | prev | next [-]

In many European countries electricity is quite expensive. In the U.K. for example, running 20 watts nonstop for a year will cost you around $65 on a typical tariff. If you have more than one home server the savings can quickly add up.

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bjackman 2 days ago | parent [-]

Also 20W is fairly low for idle draw right? Like I think you can get proper machines down that low if you know what to look for but most stuff bigger than a mini PC is gonna be drawing 40+? I might be slightly miscalibrated though.

Anyway it's not about the money for me it's any the aesthetics. Burning power for nothing is yucky.

Edit: just been Googling around. OP is running one of these HP mini PCs. They are pretty efficient! Some go well below 10W. So yeah I would say for the specific use case it's unlikely to matter very much. But still it's a useful thing to be able to do in general.

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zbrozek 2 days ago | parent [-]

My home server is a pig and draws about 100 watts idle.

	▲	bjackman 2 days ago \| parent [-]
		You should try running powertop on it. It will scrape sysfs and look for things that seem misconfigured, and suggest changes to fix them. On one of my machines it enabled some peripheral power saving mode that made a pretty dramatic saving! (I also heard that it sometimes suggests power saving modes that are usually switched off for a good reason, like apparently you really don't want some USB controllers going into certain sleep modes as they take seconds to come back).

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esseph 2 days ago | parent | prev | next [-]

Are you a programmer by chance? Some are, and they enjoy it!

I know a lot of sysadmins / platform engineer types. A lot of them really enjoy the mix of hardware and software integration challenges.

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bongodongobob 2 days ago | parent [-]

I don't know any sysadmins who would do this. Task scheduler for Windows or rtcwake for Linux. We try to reduce complexity with existing battle tested tools, not create whatever this is. This is definitely not the easy way.

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esseph 2 days ago | parent [-]

Ah, you're not a tinkerer!

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bongodongobob 2 days ago | parent [-]

I definitely am. But this is a very solved problem. It just adds brittleness to the system. Maintenance for this is going to suck. It's going to break in less than a year because you forgot to set a static IP address, or a Python library changes, or the SD card in the PI gets corrupted, or the jack on it fries, or its cheap PSU died and fries the board, etc. Then you're going to have to try to remember how the damn thing works, then figure out what other tiny change somewhere broke something. You should never add more failure points to infra, ever.

I guess everyone has to go through it.

	▲	edg5000 2 days ago \| parent \| next [-]
		I do agree that it would be nice if no external device would be needed. It does make me wonder if the Pi is truly needed. I'll be looking into this myself as well, I also have power hungry servers that are mostly idling and would benefit from WoL. In some EU countries, energy prices are truly a scam.
	▲	esseph 2 days ago \| parent \| prev \| next [-]
		> I guess everyone has to go through it Bingo, but some people never stop tinkering - their joy is in avoiding the well trod path.
	▲	littlestymaar 2 days ago \| parent \| prev [-]
		> Then you're going to have to try to remember how the damn thing works Fortunately, the author wrote a derailed essay explaining all of this… > You should never add more failure points to infra, ever. Every time you add a new system or a new feature you necessarily “add more failure points”, there's no way around that. One should avoid introducing more failure points than needed for the functionality you want, that's it. You say it's a “solved problem”, but you only give solutions to a different problem (starting the server at a scheduled time, when the author wants to start the server on demand).

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Havoc 2 days ago | parent | prev | next [-]

> a few bucks per year

Crunched the numbers for mine - about 150 bucks a year in potential savings.

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adrian_b 2 days ago | parent | prev | next [-]

The complexity in TFA is due only to author's desire to not use magic packets for waking the server, making thus the state of the server transparent for users.

If you are willing to send magic packets to wake up the server, before using it, you can save money from the electricity bill with negligible complexity.

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2 days ago | parent | prev | next [-]

[deleted]

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2 days ago | parent | prev | next [-]

[deleted]

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righthand 2 days ago | parent | prev | next [-]

Not sure where you are but energy bills are sky rocketing in the US.

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sneak 2 days ago | parent | prev [-]

The old saying: Linux is only free if your time is worth nothing.