So with my new Ubuntu server, I thought that I would shut it down everynight to save electricity, as it is taking about 100W constantly with all the harddrives spinning.
I am using an NForce motherboard, and using wakeonlan to start it up remotely, or when needed. So heres how I did it:
First I went into the motherboards BIOS and enabled all the power on lan settings, then I checked to see what the settings are on the box once it was booted.
WOL was set to ‘D’ (disabled) so to enable it:
Then I wanted it enabled everytime at boot so I edit:
And put in this line after telling the box to get its DHCP:
Then I edit these to files and remove -i
Then shutdown the machine:
And from another (Debian Linux) machine I used wakeonlan to wake it, but the crucial thing is to put the MAC address in in reverse. This is a bug on NForce motherboards so you probably won’t have to do it with others.
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not sure this will save you any power – the wake on lan functionality will require the PSU to stay powered and the motherboard etc. I guess it might save CPU power and graphics card power but that depends largely on implementation…
It does I have found, because the CPU is non functional so not drawing power and the Harddrives are completely powered down, it still powers the PCI bus of course (and probably other connections – I haven’t tested)
I have bought one of those electric meters that will tell you how much a device is pulling, and there is quite a difference between, asleep and fully on – about 70w. Which if its off for 12 hours a day for a year makes quite a saving!
cool – in which case I must try that… though can’t help feeling 30w is a bit excessive for just powering a network card but there you go.
Yes that does seem like alot, but I was also running a few other things off the same gang socket which might take that into account. I would like to just check the machine on its own at some point to get a true figure so I was looking at the difference.
But buying that device has made me change my ways slightly, I found out that my main machine with all the music equipment attached was pulling over 120w with everything off locally, so now it gets unplugged! But all my TV and video gear pulls 2w on standby, so the popular belief that standby on televisions is still drawing a lot of power seems to be wrong in my case.
Yes 2w doesn’t seem much – it would be interesting to see what that worked out as carbon emissions over the year. Can’t find anything online but it’s definitely worth doing the calculation. I guess I should start making the effort
I believe this issue is fixed in v7.04 (“Feisty Fawn”), as it uses v0.59 of the forcedeth driver.
(I had similar trouble with Edgy on my amd64 machine. I actually downloaded the latest drivers at the time and compiled them myself, which fixed the wol issue, but broke my network statistics.)
Thanks for that. Now I have a machine that happily wakes up remotely.
Any idea how I can get it to resume from suspend – you’d think it would be easier, but no
I don’t think that you can resume from a suspend, I don’t think that it puts the machine in to the correct state. Thats why I use halt.
Thank you for this, I have spent AGES trying to get this working, and then I read
“put the MAC address in in reverse”
and this is the first time I’ve read that
try it out and it works first time
Thank you :D
Thank you for the MAC in reverse tip, I’ve been tearing my hair out trying to get my Windows Server 2008 to WoL. I assumed it was a hardware issue since the whole idea is that the machine isn’t running after all… As for the power savings debate I just wanted to throw my 2 cents in, the NIC is not actually drawing power from the PSU for WoL functionality, rather it’s getting its power over ethernet, the voltage is very low and the vast majority of network cards remain powered as long as they’re connected via ethernet regardless of WoL settings.