Alright this tutorial is under the assumption that you have a motherboard or nic that supports wake on lan (WOL.)

Once you have confirmed this and turned it on if it isn’t already, boot up Centos and we will start.

1. Create this file /usr/bin/activatewol
2. Add this to that file

#!/bin/bash
ethtool -s eth0 wol g

3. Now go to edit this file /etc/sysconfig/network-scripts/ifdown-post and /etc/sysconfig/network-scripts/ifup-post

4. In both files just before the end } tag add this to both of them:

ethtool -s eth0 wol g

5. Once you have done that set permissions on the activatewol file

chmod 755 /usr/bin/activatewol

6. Restart your network

service network restart

7. Run ifconfig to get your MAC address to send the WOL packet to this machine.

8. Test it, generally I use it to wake my backup server for backups and other things. So I would run the command

pm-hibernate – (Assuming you have pm-utils installed in your copy of Centos.)

Once it is in full hibernation mode, send your WOL packet to your Centos Machine and it should awaken from its hibernation!