When sending a TERM signal to the kolabd master process `kill $(cat /run/kolabd/kolabd.pid)` the pidfile gets removed but the main process and it's childs doesn't stop. The childs never receive a kill signal and the master process waits until the childs will stop (which they never will).
Only `killall kolabd` will help. This is also the cause why the start-stop-daemon script fails when using the --pidfile options.
Solution is to kill childs created by multiprocessing when terminating the master process.