ubuntu server 12.04 lts is there a way to enable sleep mode and wake on lan?

Question

I was wondering if it were posible to make my server go to sleep after a set period of time, but still be listening for lan requests. I use my server as a media server that might get used 3 or 4 hours a day and it is really a waste of power to have it running all the time. However I don't want to run up to the second floor to switch it on when we want to watch a movie. I saw a few posts about stopping this from happening but how do you enable it?

Answer 1

Wake on LAN is a BIOS and NIC feature, not an OS feature, that is, you need a supporting BIOS and NIC to do it.

Once you've enabled it in your BIOS (if you can), you can check if your NIC has WOL support enabled by checking the output of ethtool [interface].

If the value of Supports Wake-on contains g, your NIC supports WOL magic packets.

To check if it is actually enabled, take a look at the value of Wake-on. If it contains g, your NIC has magic packet support enabled.

If it isn't enabled, run the following:

ethtool -s [interface] wol g

You'll have to issue this command every time your system starts, so add it to the appropriate place. In Ubuntu, perhaps the best place would be as an up rule in /etc/network/interfaces, or the equivalent for your network manager.