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7 Sensors on server went into an UNKNOWN state



I am running PRTG Network Monitor Server OS: Windows Sever 2008

Last night I had 7 sensors on a server go into an unknown state. I had one other sensor that failed and alerted me of an issue. When I checked the server, the ping sensor was good, but the rest were not. They were in an unknown state for over 9 hours. All of the sensors stated they had not received any data in 9 hours 34 minutes and that I should check the WMI delay. This is the only server that is having this issue and was fine last night. The rest of our servers and the probe are all fine. Why didn't the sensors go into a "DOWN" state after not receiving the data required? All of the sensors are WMI senors that monitor either a service or disk space. Is there a way that I can force the sensors to a DOWN state if this happens again?


John Miller

wmi-free-disk-sensor wmi-logged-on-user wmi-service

Created on Aug 12, 2011 2:41:59 PM

3 Replies



Dear John,

may I ask to which scanning interval these sensors are set to?

best regards

Created on Aug 15, 2011 12:56:14 PM by  Torsten Lindner [Paessler Support]



Hello Torsten,

They are just set at the default levels. I have not changed them. I just checked and they are inherited from the server which is set at 5 minutes. Strange enough, I created new sensors for the server and they are working fine. I paused the other sensors.

Any ideas?


John 4323

Created on Aug 22, 2011 8:58:24 PM



Please try if restarting the PRTG Probe service also brings the old sensors back to life.

Created on Aug 23, 2011 1:00:05 PM by  Torsten Lindner [Paessler Support]

Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.