We should support some configurable alerts for HA. At a minimum, if the free space remaining on the volume for the service directory, log files, journal, HALog files, or snapshots falls below a minimum threshold then force the service into an "OPERATOR" state. Those alerts might be simple stubs in the Configuration file or automatically provided with minimum thresholds for key disk locations. Other kinds of alerts could also make sense. We monitor a lot of things and could provide reporting on those that are critical.
However, this sort of thing is best performed using a dedicated monitoring package such as nagios.