I actually meant to bit-bucket this and start over once my brain kicked
in. (Sadly, habit had me hit "Send" instead.)
When it comes to VM's, in my case, it's quicker and easier to have the
host suspend all it's children, rather than shut them down. This may
not be a good answer with a large number of child systems, if the time
required to suspend them all is greater than that to shut them down or
if the available runtime isn't that long; but in my case a suspend takes
only a few seconds.
The other benefit being that they're back online faster after the restart.
Mike.