Hello all, I'd like to find out more about what the systemd does during shutdown/reboot. I knew pretty well what old sysVinit does, but my long experience is worthless with systemd, and I have to learn anything anew :(. I accept RTFM answers if they include links ;)
The problem I have is partially related to https://bugs.debian.org/cgi- bin/bugreport.cgi?bug=751636 In my eyes it seems that systemd shuts down everything in parallel, including networking. So it can stop network quite early, before other services. Thus SSH connection just hangs, instead of proper disconnect. That can be solved by installling libpam-systemd - SSH session closes immediately after issuing reboot. However I would prefer, that SSH is not stopped until all other services shut down properly, so that if something goes wrong I can still connect and investigate or fix it. As an example - a virtual machine in libvirt/KVM/Qemu, that for whatever reason ignores the ACPI button, and does not shut down. Yeah systemd will kill it eventually (5 minutes or so), but I would prefer to log into such machine and issue correct shutdown. Unfortunately the neworking was gone at that moment. Another similar bug (hopefully fixed now), was that bind for some reason did not shut down on SIGINT/SIGTERM, and the init script was waiting forever. Without SSH stil active I would have to power cycle the server. (which is a bit more complicated with remote servers). So what I would like to achieve is to set somehow the dependencies in systemd, so that networking is deconfigured only after all services are stopped, and that SSH is the last service to stop. Perhaps this should be a bug report against systemd, but I wanted first to know if I'm not missing something that is obvious for those who know systemd better. -- Best Regards Vladislav Kurz