Has anyone else noticed the classroom machine runs for up to 30 minutes after you select shutdown? It then is in a state you cannot access it and it stays in "shuting down" mode.
This is actually a known bug in early versions of RHEL 7.x.
What is the actual problem? When you choose to "shutdown" most environments send an ACPI (power button) event to the running VM. The problem is that if the VM is at a graphical login prompt, the ACPI event is "trapped" by gdm (Gnome Display Manager) which *drops* the event. If you have logged in first (or switched from graphical.target to multi-user.target - aka no graphical login), then the ACPI event is properly handled, meaning a shutdown is initiated.
A thirty minute timeout is the online environments *punt* if shutdown hasn't finished and actually pulls the proverbial power cord. Our ILT (RHA DIY) environment has smaller timeout values for "rht-vmctl stop VMNAME" which mirrors the same activity.
This problem is fixed in later versions of RHEL 7.x but some of the older courses are still subjected to the problem until they are updated.
Highlander of UCF (the classroom environment)