How to find out why server turned on

Question

I have a PC running as debian server. Usually, the server is shut down until I press the power button or send a Magic Packet via WakeOnLan.

But sometimes, the server turns on alone.

How can I find out why the server turned on?

I already took a look at my syslog file: https://pastebin.com/FU207KDc but coudn't find the cause.

Arch documentation to the rescue ... Arch: Wake-on-LAN ... "It is known that some motherboards are affected by a bug that can cause immediate or random wake-up after a shutdown whenever the BIOS WoL feature is enabled " ... Arch Reference Thread — RubberStamp, Dec 01 '17 at 03:48

score 0 · Answer 1 · answered Dec 01 '17 at 02:44

It depends on BIOS vendor and type, but in most cases you can:

dmidecode | grep "Wake-up Type"
        Wake-up Type: Power Switch

If you don't have dmidecode command, you need to install it:

apt install dmidecode

You can look at this answer to find out how to retrieve more information from your BIOS.

1 Answers1