<%NUMBERING1%>.<%NUMBERING2%>.<%NUMBERING3%> PRTG Manual: PRTG Housekeeping

Once you have prepared your IT infrastructure and set up the devices and sensors you need for monitoring your network with PRTG, you can let PRTG do its work. However, you should regularly review your setup to keep your installation of PRTG up to date and ensure the best possible monitoring for your network. In this section, you find some tips on what to check in your PRTG installation and, if necessary, how to clean it up.

Here are quick links for ease of use.

General Issues

  • Check if you still have your license document. If not, you may think about requesting your license from Paessler anew.
  • Check if the customer contact details (including VAT identification number) that Paessler has from you are still valid. If you need to update your data, do not hesitate to contact us.
  • If you use your own SSL certificate and not the default Secure Sockets Layer (SSL) certificate delivered with PRTG, check if your certificate is still valid.
  • Regularly check our Paessler Blog and/or subscribe to our weekly newsletter to stay up to date regarding PRTG Network Monitor and other IT-related content.

License and Version Check


  • Check if your license is still up to date. You can view the activation status of your PRTG installation under Setup | License.

icon-prtg-on-demandThis option is not available in PRTG hosted by Paessler. For PRTG hosted by Paessler, log in to your PRTG hosted by Paessler instance and manage your subscription via the Dashboard tab.

  • For a quick overview of your license status, go to the Welcome page. There you can see how many maintenance days you have left and the number of sensors available to you.
    icon-i-roundThe number of available sensors that is displayed here does not consider sensors in a Paused status for technical reasons. However, sensors in a Paused status are not included in the maximum number of sensors that your license allows. Add the number of your sensors that are in a Paused status to the displayed number to know exactly how many sensors are still available on your installation.

Software Version and Server Information

  • Check if you run the most recent version of PRTG. You can view your PRTG version under Setup | PRTG Status, section Software Version And Server Information. The version number consists of the following parts: year, quarter, version, build. For example, if your PRTG version is, this means that you have installed version 52, build 1161, which was released in the second quarter of the year 2019.
  • Check if your currently selected release channel is still the one that fits your monitoring requirements. You can view the release channel you use under Setup | Auto-Update | Status. Available channels are Stable (most conservative option), Preview (thoroughly tested), and Canary (for testing only). To select a different release channel, click the Select Other Release Channel link.

icon-i-roundYou can also view your installed PRTG version and release channel in the footer of the PRTG web interface.

System and Performance Check

Overall System Status

Check your overall system status under Setup | PRTG Status.


What to do

Software Version And Server Information

Check your Server CPU Load. This value should be lower than 50%.

icon-book-bulbFor information on how to improve your system performance, see the Knowledge Base: How can I speed up PRTG—especially for large installations?

System Startup Log

  • Check if the log of your last system startup is OK all in all.
  • Check when the last system restart took place. If it has been more than one month, we recommend that you restart your server. Optionally, you can combine the restart with the installation of the latest Windows updates.
    icon-i-roundTo schedule an automatic probe restart (for example, for the local probe or a remote probe), go to the respective probe’s Settings tab, section Scheduled Restart Settings, and select your favorite Restart Option.

icon-book-bulbFor further logfiles and where to find them, see the Knowledge Base: How and where does PRTG store its data?

System Warnings

Check if your system warnings say None.

System warnings that might be shown are, for example:

  • The available diskspace is too low!
  • The available memory is too low!
  • Connection to database lost!
  • No configuration file found, but monitoring data for an unknown configuration exists!
  • This beta version has expired
  • The path to PRTG’s configuration file (%s) could not be found. Please check network paths if applicable.
  • Internal error. Restart of PRTG required.
  • The license of this cluster member is not valid for operating in the configured cluster.

Sensors by Interval

  • Check how many sensors have a scanning interval of 300 seconds or even fewer.
  • Ask yourself if the chosen scanning intervals really make sense regarding the performance impact of the respective sensors on your system. Shorter scanning intervals usually do not give you more accuracy but cause unnecessary load on your machine and the network. For example, does a WMI Free Disk Space (Multi Disk) sensor really need to scan your disks every 60 seconds, or is it really necessary to search for Windows updates more often than once every 24 hours?

icon-i-roundTip: Change the scanning interval in the Root Group Settings and use the inheritance mechanism of PRTG to use this interval for all objects that are below in the object hierarchy.

System Settings

  • Check if your web server ports are still correct.
  • If your PRTG system is reachable via the internet, we recommend that you prevent communication via port 80 (HTTP) and that you only use port 443 (HTTPS). To change the web server settings, go to Setup | System Administration | User Interface, section Web Server, and select a TCP Port for Web Server.

Web Server Activity

Check the Slow Request Ratio. This value should be lower than 10%.

Background Tasks

  • Check if there are any scheduled auto-discoveries that you do not need anymore. You can view a list of all existing or running auto-discovery processes under Logs | System Events | Auto-Discovery.
  • Check if similar sensors detection is enabled on your system. If you do not need this analysis (which runs with low priority in the background), go to Setup | System Administration | Monitoring and select Turn analysis off.
  • Check if recommended sensors detection is enabled on your system. If you do not need this analysis (which runs with low priority in the background when you add a new device, when the last analysis was executed more than 30 days ago, or when you manually start it), go to Setup | System Administration | Monitoring and select Turn sensor recommendations off.

Libraries and Sensors

  • Check if all your Libraries are up to date. Remove all (default) libraries that you do not need.
  • Check if there are any sensors that are still monitoring your network although you do not need them for your infrastructure, particularly if they have a high impact on system performance. For example, this includes the following sensor types: Sensor Factory, Packet Sniffer, VMware, Email Round Trip, SQL Server, CloudWatch, QoS, File, Folder, HTTP Full Web Page, and custom EXE sensors. Set the sensors to a Paused status if you do not want to completely delete them from your system.
  • Check the number of channels per sensor. Sensors with more than 50 channels can have a high impact on system performance.

User Accounts

  • Check if your user accounts and user groups are still up to date. Update user contact details (email address, phone number) if necessary, or disable users that do not work with the respective installation of PRTG anymore. Always keep in mind that multiple user accounts and groups can slow down web server performance.


  • Check if the Maps you created are still in use or if you could delete them.
  • Check if there are any broken links in the maps that might need correction.
  • Check if you can still retrieve embedded HTML objects and frames.


  • Check if the contact details (email address, phone number for SMS) in your notification contacts are still up to date.
  • Check if custom notification templates are still in use by clicking the Used by button button_used_by under Setup | Account Settings | Notification Templates.
  • Check if there are any new default notification templates that might be of use for your specific setup.
  • Check if your notification templates still work by clicking the Test button button_test under Setup | Account Settings | Notification Templates.
  • Check if there are any error messages regarding notifications under Logs | System Events | Notifications.

Data Storage and Backup

  • Check for how many days different kinds of data are kept and if you might be able to optimize your settings so that the file containing this data does not get too large. To change the settings, go to Setup | System Administration | Core & Probes, section Historic Data Purging.


PRTG Manual:

Knowledge Base: How can I speed up PRTG—especially for large installations?

Knowledge Base: How and where does PRTG store its data?

Knowledge Base: How do I back up all data and configuration of my PRTG installation?

Knowledge Base: How can I move (migrate) my PRTG installation to another computer?

Knowledge Base: My PRTG has crashed and I can’t restart it anymore. What can I do?

Paessler Blog: 7 Useful PRTG Support Resources You Should Know

Paessler Website: Release Notes for the “Stable” Release Channel