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Data loss and abnormal sensor data after upgrade to version



I upgrade from PRTG V7.2.1.4722 to V7.3.5.5788 today.

The upgrade was smooth and successful.

Two things is bothering us:

1. After the upgrade, data was lost from 7:10AM until 12:25PM. (The upgrade was done at around 12:00 noon or so). This happens to all device monitored by PRTG including the probe device itself. What went wrong? Is it possible to retrieve those data back?

2. My colleague who has a Linux sensor told me that one particular sensor that perform Oracle query to our Oracle server shows a significant increase in response time compared to before the upgrade to new version. Is there any problem with the new version or any fine tuning we need to do?

I know it's not possible now but I would be glad if PRTG could provide a way for client to upload screenshots and sensor data file via this web support tool for analysis purposes.

Kindly advice.

Thank you.

7-3-5-5788 linux prtg response-time

Created on Jul 22, 2010 9:59:26 AM

Last change on Jul 30, 2010 9:01:05 AM by  Daniel Zobel [Product Manager]

1 Reply




This might be just a caching issue, PRTG does save historic much more often (about every 5-15 minutes). Please try the following:

  • Stop both PRTG services (core and probe).
  • Head to your data folder (can be discerned from the Server Administrator tool, under the "Core Server" tab)
  • Delete the "PRTG Graph Data Cache.dat" file
  • Restart the PRTG services
  • Log in to the Web GUI
  • Go to "Setup -> System Status" and check the background tasks. It should state that it is calculating historic data


  • Refresh the page from time to time (is the number being reduced?)
  • Let it run until it is done and then take a look at the historic data of your sensors - it should now be available

This might be due to some internal changes we have made to the Oracle sensors between 7.2.x and 7.3.x. Fine-tuning options are not available.

Best Regards.

Created on Jul 23, 2010 10:39:56 AM by  Torsten Lindner [Paessler Support]

Last change on Jul 30, 2010 9:02:19 AM by  Daniel Zobel [Product Manager]

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.