If everyday actions on your Debian Jessie with systemd start to hang forever:
- Pulseaudio clients cannot connect to their servers any more…
- “ifup” of a network device needs to be Ctrl-C’ed (but has accomplished its work)…
- Trivial daemons refuse to start with “systemctl start”…
…then it might be that systemd has choked on something and needs to be restarted. Fortunately, that is possible without any reboot or log-out:
systemctl daemon-reexec