I fixed problem by adding this line to my /etc/init/ modem-manager.conf :
stop on runlevel[0]
Now my shutdown time has been brought down to nearly 5 seconds (from 15-20 seconds).
I fixed problem by adding this line to my /etc/init/ modem-manager.conf :
stop on runlevel[0]
Now my shutdown time has been brought down to nearly 5 seconds (from 15-20 seconds).