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Making a Linux home server sleep on idle and wake on demand (2023)

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Ha ha, I tried something similar when I had to go to Thailand for my wife's treatment. And failed spectacularly. Fortunately, my laptop had all the files. I didn't have Tailscale at that time.

My Desktop, WoL on, tested to be working Android Phone, always on

All have SyncThing installed. Mobile had Tasker installed.

So, the idea was to have Tasker monitor a folder inside SyncThing, When I need my computer, I put a file inside that folder, when Tasker finds that folder, it sends WoL to my desktop, and deletes the file, Computer wakes up. When I see the file deleted I know, the beast is now awakens ....

When I actually did try that from Thailand, the file did not got deleted, nor the beast woke up.

What happened? Turns out, my mobile restarts automatically after some time of inactivity. Which, locks Tasker out, and the whole process fails.

So, operation wake the beast was busted.

5 months agoby t_mahmood

20 years ago, I used to have a Linux server running Slackware at home, that would wake up the two PCs we had at home to back up their data if they were turned off. If they were already turned on, they would send a WOL packet to the Linux server to turn it on in case the that server was off, and then start the backup routine. And the last one would tell the Linux server to turn-off itself. It used to work really great, good times.

5 months agoby leandrosa81

Some motherboards disable power to their ethernet port upon sleep and so WoL will not work.

This is particularly common if the NIC is a power hungry 10GbE port.

However, in the particular case I found, the motherboard also disables oower to any usb GigE adapter attached.

The solution I found was to attach a USB hub with (empty) SD slots and integrated GigE port. As SD cards require power to remain mounted, the motherboard did not shutdown power to this adapter and WoL worked.

5 months agoby bjt12345

Well done. But note: you can grab an ATX control board, or configure the RPi as a USB Gadget to wake the machine via power button or keyboard.

5 months agoby privatelypublic

Not as sophisticated as your solution, but works with all hardware for the "backup use case": use a mechanical timer set to 10 minutes before backup starts (and power off 30 minutes after backup normally ends):

https://www.amazon.de/Mechanical-Analogue-Switching-Christma...

It's a more rigid solution that doesn't let you ssh in (unless during backup time ;-), but it saves electricity and it is implemented in 10 minutes (5 for an Amazon order and 5 to plug in and set the timer to your backup hours). It's also a more robust solution - little can go wrong (the only thing is you need to balance backup time against electricity/time savings as backup size grows).

5 months agoby jll29

That's what I was thinking too. My home server consumes like 15 W and is silent. If you get a rack mounted server made for data centers and stick it in a closet so you can't hear it then yes, i guess this approach makes sense.

5 months agoby antov825

(2023), discussed at the time: https://news.ycombinator.com/item?id=35627107

5 months agoby flobosg

Thank you for the post, very informative. I do this half manually. I have a cgi script on the always on very power efficient sbc server that wakes up the bigger server if someone needs it. The big server powers itself down when no backup is running at a time everybody using the server usually sleeps. I thought about improving this and measure server usage and solar power generation to decide the shutdown, maybe with an additional warning email. for example: "The server shuts down in 5 minutes due to no demand and no solar power, if you want to prevent this click this link: http://server.lan/cgi-bin/keepalive "

5 months agoby john61

Have you measured the power consumption of your "high power consumption" server?

5 months agoby 2OEH8eoCRo0

I considered doing something like that but eventually I went for the simpler solution of plugging my little servers into smart plugs. I shut them down, then power off the plug over wifi. I start them by powering on the plugs. The plugs draw very little power. The servers are ARM SoC and draw 1 to 4 W. One of them has an HDD that draws about 10 W but I can unmount and power off it when I don't need that disk and I still need the server on (it's also got a SSD.)

5 months agoby pmontra

This reminds me of this old plugin for Windows Home Server: https://www.green-it-software.com/products/lights-out-for-wh...

You could set a calendar schedule for waking up itself and backing up the clients, and at night the server would go into standby only if no clients were running anymore since X minutes.

5 months agoby hs86

My server stays powered off but will boot on receiving wol packet. It’s not a sophisticated set up but works for me. I have an always on Rpi running tailscale. I can ssh to it and send a wol from there. Once my server boots I can ssh to it and run the script to mount its data disks - they are encrypted so I need to type a passphrase. Quite a bit of work but I don’t have to do it often.

5 months agoby InfamousRece

I would be tempted to try using the Pi as a router & firewall with the server on another subnet, having it wake the server using traditional WOL as needed. That feels simpler to me and more controlled. But my overall feeling is that not much power is saved here overall compared to a well set up server. Good project though quite educational.

5 months agoby Neil44

Use `powerprofilesctl set power-saver` to set to a low use profile

5 months agoby ape4

https://blog.ctms.me/posts/2024-08-29-running-this-blog-on-a...

Does a Pixel 5 have wake on Lan? Do any cellphones?

5 months agoby ForOldHack

I recall this being quite simple last time I tried, just enable WoL in bios and run etherwake from my router (or from some other machine on the network).

But this is about waking up on non-magic requests, just any request?