Wake-on-lan to trigger virtual-machine with kvm and libvirt

You could use /etc/rc.local or some system boot scripts, but this wouldn't be the best way to do it. On startup your network interfaces are configured, sure, but there are other times when your network interfaces may be brought up or down and you will need this executed during those times.

You want to edit /etc/network/interfaces:

You should have a line like:

iface eth0 inet static

Underneath that, indented further, you want to create a post-up and post-down commands e.g.

iface eth0 inet static
    post-up /usr/sbin/ethtool -s eth0 wol g
    post-down /usr/sbin/ethtool -s eth0 wol g

Obviously, replace eth0 with the relevant interface if different.

See interfaces(5) for more information on post-up and post-down commands

man 5 interfaces

When powered down to the correct state, name name of which varies from brand to brand of motherboard, not only is the NIC left partially powered on (you'll see the lights blink due to traffic on the network) but the motherboard itself has certain circuitry powered up. That circuitry responds to the signal from the NIC telling it to power back up. Other shutdown modes will prevent one or both those components from being powered up, so the wakeup signal is either not recognised by the NIC or the motherboard doesn't see the signal from the NIC.

As far as "solving" this goes, I have no real ideas. I've also been struggling for years to get it consistently right. Every time I get a new machine I have to start all over. Further, some machines are more cooperative in this regard than others. Some I've had will sometimes wake up but other times won't, even when they've been shut down the same way every time.

My only conclusion is that this is one area the manufacturers need to come to some sort of agreement. They could start with some consistent naming scheme for the various power states.

I better stop there, otherwise people might get the idea this is a pet hate of mine.