More often than not we need to do a restart for some reason or other. Or our system is chugging a bit. But assuming that everything is humming along nicely and there is no pressing reason to reboot do you let your let your VM get as big as it wants to as long as there is plenty of room. Or do you reboot regardless of need if it gets past a particular size. If so what is that size. Also how big have you allowed you VM to grow.