On 14/06/2015 11:58, KatolaZ wrote:
Sorry for asking a silly question, but what's the problem in having cups "running" all the time? And better, if you start/stop cups when you need it, why should cups notify systemd (or any other init) that it is ready to do things? Why should init be informed of the fact that a daemon is running or not, except maybe at boot time, and just for the sake of allowing parallel boot?
It's not about parallel boot, it's about reliability, even in the case of sequential boot. It's also not about notifying init, it's about notifying services that depend on it, which is generally handled by a centralized service manager - and systemd is such a centralized service manager that also runs as init. Say you have an awesome automatic Web printing service; it should not be activated before CUPS is ready, else it will not work and clients will complain. How do you make sure you don't start it too early ? The historical solution is to sleep for a certain amount of time, but this is ugly, because either you don't sleep enough and it still fails, or you sleep too much and you waste time. The correct solution is for CUPS to tell your Web printing service when it's okay to start - but since CUPS doesn't know what depends on it, it can only notify its manager, which will then take care of things. Of course, you might not have a use for the mechanism, and if Devuan's only intended audience is desktop PC users who don't care about reliability, then it does not matter. But readiness notification is a real engineering issue that needs to be solved. -- Laurent _______________________________________________ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng