Applies to ONTAP Select ONTAP 9 Issue Node not serving data. Following notification is displayed: System Notification (ROOT VOLUME NOT WORKING PROPERLY: RECOVERY REQUIRED) EMERGENCY Vol0 is full / low...Applies to ONTAP Select ONTAP 9 Issue Node not serving data. Following notification is displayed: System Notification (ROOT VOLUME NOT WORKING PROPERLY: RECOVERY REQUIRED) EMERGENCY Vol0 is full / low on free space.