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Legacy PRTG (v5) stuck on "reading historic data"



I have a legacy (v5.x) install of PRTG. I recently rebooted the server after it had been running for a long time (year +). PRTG fails to start as a service. When I try to start the GUI it does the initial startup stuff and then guts stuck at "reading historic data 378/512". I know that there is a folder for each day of monitoring data and there are only 375 folders in the directory. PRTG is set to keep data for only 180 days and I manually remove the monitoring folders after ~ 1 year. So it seems to be looking for data going back 512 days and hangs when it can't find it. How can I set it to only look for data for the last xxx number of days?

data historic legacy prtg read

Created on Jul 13, 2010 12:17:11 AM

2 Replies



Actually, under PRTG 5, the number of data sets calculated for the cache does not necessarily mean the number of days the data is stored for. As such, 512 data sets do not necessarily represent 512 days.

In this instance it ist most likely PRTG is hanging up on a corrupted data set file. Try stopping the PRTG processes, then deleting the cache directory located in the PRTG data directory and restart PRTG.

Does it hang up again?

Created on Jul 15, 2010 2:23:47 PM by  Patrick Hutter [Paessler Support] (7,225) 3 3



Even after deleting the cache and removing all the monitoring data in the sub directories of "monitoring database" It will still get stuck at the same point. Then I went in to: default.csv and default.prtg and removed the 378th sensor entry

After that it worked fine, even when I brought back the old monitoring data.

Created on Jul 23, 2010 9:23:25 PM

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.