Automatic shutdown using ping
 

Hi all,

I have set up a Linux server to serve various devices (i.e. MP3 playback in the living room). The server automatically starts up using wake on LAN.

I would like the server to shutdown automatically as well. I think about a script using "ping" to check if any of the served devices is up (using a list of IP addresses) and shutting down when none is available for 15 minutes.

Did anybody already do this or has another solution and can provide a matching script?

Not sure if ping is the right solution. A lot of services use icmp to check availability of a host so this could result in the server going down randomly. I once read a LJ article on port knocking. The idea is to parse the firewall logs for a certain knock sequence and then take appropriate action. Like opening up a port or something. This sure can be expanded to call shutdown on receiving a predefined shutdown knock sequence.

Here's the article:
http://www.linuxjournal.com/article.php?sid=6811

edit:
oops. I guess I misread your question as well. The keyword being automatically shut down the server... Yeah, then the port knocking thing is not such a good idea.

wrong - i misunderstood what u asked :(

Does your distro and hardware support ACPI? You could just use that and set the monitor, HD, and system to shut down after 15 min inactivity.

Thanks for all the replies.

I do not think ACPI will do the job since there is no way to define "system activity" as "is the server serving any clients". As far as I know it rather reacts on mouse and keyboard activity. I can use it the stop the HD when it is not accessed and thereby saving some energy and reducing noise, so thanks for that idea.

What I am looking for is completely shutting down the system when it is not needed. And for my purpose not needed means that no potential clients are up and running. That's why I thought ping might be the solution.