Run command when network goes down?

English Network/Internet
1

Hi,

I’m using rsync via cron to synchronize files on my laptop with a drive on my network. This usually works fine, but because I’m doing it over a WLAN, I run into problems if the network connection fails. The script that cron runs checks for a network connection before running rsync, but if the network goes down after that check, I run into problems.

I thought I could solve this if I were able to kill rsync automatically if the network goes down. Is there some way to configure this? I tried putting a script with “killall rsync” into /etc/sysconfig/network/if-down, but the script was not executed. Does anyone know how to make this work, or know of a better option?

Thanks for your help!

(SuSE 11.0; KDE 3.5; using knetworkmanager)

2

The problem is that the network going down, as opposed to the network being explicitly taken down, is not something that’s easy to detect. From the standpoint of an app, a down link is hard to distinguish from one that’s taking a long time to reply.

However rsync has a --timeout option which you could use to shutdown rsync if it takes too long to get any response.