When installing some packages with yum I see the text:Running transaction (shutdown inhibited)What does it exactly mean? Would it prevent me from shutting down the system if I typed shutdown -h now in another terminal? That is, what kind of inhibitions does it prompt?
Running transaction (shutdown inhibited) how much inhibited is shutdown?
fedora;yum
This is a feature of systemd 183 and newer, documented most fully in the Inhibitor Lock Developer Documentation. You can also look at the man page for systemd-inhibit  and for that matter, you can use that command to run another command with an inhibitor taken.The things that can be inhibited include:shutdownsleepidleplus handle-power-key, handle-suspend-key, handle-hibernate-key, handle-lid-switchYou can see the currently-held inhibitors with systemd-inhibit --list, and for example on my system I see  Who: mattdm (UID 18281/mattdm, PID 4207/gnome-settings-)What: handle-lid-switch Why: Multiple displays attachedMode: blockamong others.When applying updates, Yum (and now DNF, and as I recall actually RPM itself via a default plugin) takes out a block inhibitor against idle and shutdown (but not sleep), to keep you from accidentally powering off your machine mid-transaction and potentially messing up the system (with a package halfway overwriting an older one). This can, however, be overridden using the -i (or --ignore-inhibitors) option for systemctl (usually with poweroff or reboot in this case).I'm not actually sure what happens if shutdown is used to power off or reboot at a given time and an inhibitor is active when the time expires.