My ubuntu is slow to shutdown, and the culprits seem to be modemmanager and something called nm-dispatcher.action.
On shutdown I get a message on the terminal saying something like "asking all remaining processes to terminate" and then there is a ~5 second delay, before unresponsive processes are forcibly killed.
One of them was modem-manager, and I don't have a modem so I fixed that one with simply sudo apt-get remove modemmanager and there doesn't appear to be any side effects.
The other one is something like "nm-dispatcher.action: Caught signal 15, shutting down. …" which I was able to fix by removing network-manager and network-manager-gnome. But then, obviously, I don't get the network manager icons and stuff which I need in gnome-shell. I have tried wicd as a replacement, but it is not working to my liking.
So how can I prevent those processes from hanging during shutdown?
Best Answer
Here is the bug report on, no sign of a fix.
https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/869635
The report does mention an edit one can make to /etc/init/network-manager.conf, ie. add as shown
I believe adding the line was effective here though myself use Wicd & have removed network-manager. YMMV, if trying & it causes issues then remove the added line