I wrote a script that suspends all my VirtualBox machines, and put a line in /etc/rc.local.shutdown, but it doesn't seem to work,su - XX -c /XXWhen I'm booting the next time, VirtualBox tells me the machine was  Aborted, so the script wasn't executed. (Launching that script manually works for me)P.S I already enabled shutdown.targetEDITThe problem seems more complicated than I thought, in my .bashrc, if it's running on tty3, it executes startx, so when systemd decide to shutdown/reboot, it whould kill VBoxSVC process and other stuff when X Session dies.I also tried to hack the source code of xfsm-shutdown-helper, make a fake systemctl that  execute my script first, none of the above works.
Using systemd to execute a script before system shutdown?
systemd;shutdown