Reboot Linux Client on Network Disconnect

grande25 · 10-13-2008, 09:52 PM

Question: Is there a way to force a reboot on a remote linux client when connection with the server is lost/broken?

Background: Server sends IP Video to Linux client. When power is lost or network goes down, the Linux client continues broadcasting the last server transmission which is BAD. If I could restart the Linux client it would cease to transmit the outdated info and be ready to post updated data when power/network connectivity is restored.

Iz

kenneho · 10-14-2008, 02:12 AM

You could make a cron-job that checks the network status (and other things as well) every X minutes, and reboots if it finds an error.

Another thing would be to use a network power switch. That way you could (automatically) log into the power switch and reboot the failed server.

I'm sure there are plenty of other ways to do this, but it depends on your current setup and so forth.

chrism01 · 10-14-2008, 02:47 AM

You only need to restart the network service. This isn't Microsoft.

grande25 · 10-19-2008, 09:40 PM

Okay, I'm using VI and this is the first script I've ever run. I can get the script to run and it pings the server IP just fine. Problem is when I unplug the server and the IP pings fail it doesn't execute the reboot as I'm trying to make it. I've adjusted priveleges to be sure users can run the command. I'm getting a syntax error that i'm making an "unexpected end of file" argh! Here is the script I have:

Ping -n 123.45.678.910
if %errorlevel%==4 shutdown -ar -t 5

When i run this script and the server is connected to the LAN i get a nice steady stream of pings. When I unplug the cable the stream stops and what should happen is a reboot. However it just sits there. When i hit Ctrl+C to stop the script it gives me the syntax error: unexpected end of file.

Please help

grande25 · 10-20-2008, 09:20 AM

Bumping...

chrism01 · 10-20-2008, 07:00 PM

I don't recognise this syntax

if %errorlevel%==4 shutdown -ar -t 5

looks like DOS batch cmd.

Try reading these:
http://rute.2038bug.com/index.html.gz
http://tldp.org/LDP/Bash-Beginners-G...tml/index.html

I'd recommend sending 1 ping, then checking the exit code eg

Code:

broadcast="up"
while true
do
    ping -c 1 123.45.678.910>dev/null 2>&1
    if [[ $? -ne 0 ]]
    then
        if [[ $broadcast = "up" ]]
        then
            <stop broadcast program>
            broadcast="down"
        fi
    else
        if [[ $broadcast = "down" ]]
        then
            <start broadcast program>
        fi
        broadcast="up"
    fi
done

no need to reboot anything. Optionally you'd want a sleep cmd at the bottom of the loop, otherwise it'll hammer the cpu. Sleep is normally in seconds eg

sleep 10

sleep for 10 secs.