Emergency UNIX and Linux Support

Hi,
I am a sysadmin. During long weekends i need to turn off all machines in my lab. Is it possible to shutdown systems using ip address without using ssh.

i read somewhere that shutdown -m "IPADDR" may work. However it seems its a windows specific command.

So my question is how do i remotely shutdown all machine in my LAN using their IP address.

just write a script that does the shutdown for you...

How do i write that script? Writing a script that ssh to each system will be very tedious as i ll have to first create public key pair for around 100 systems. Is there a easier/simpler way to do this?

Yes. Create 1 key-pair & copy it to all 100 systems. You don't necessarily need a different one for every system.

or use "expect" to spawn a ssh session and send the password to the servers...

Their solutions were "push" solutions. You could do a "pull" solution: Write a cronjob to run every minute (or 15 minutes, or whatever); it uses curl to check a web page on your server; if the file exists, the cron job initiates a local shutdown.

Code:

  if curl -s -i -I http://my.server.ip:port/power-off-`date +%F` | head -1 | grep " 200 OK" >/dev/null ; then 
        shutdown -h now
  fi

On the server, simply run a web server and point the document root somewhere you can write to, and when you want the systems to shut down, simply cd into the web server's document root directory and do:

Code:

   touch power-off-`date +%F`

The date makes sure the systems dont power off at startup the following day.

If you want to make it secure, generate a self-signed SSL key and distribute the cert to all the hosts.

I manage 248 servers and use pludi's method. Makes pushing out updates much easier too