PRTG Manual: System Health Sensor

The System Health sensor monitors internal PRTG parameters. It shows the status of the system on which a probe runs. PRTG creates this sensor type automatically and cannot be deleted.

It checks various parameters of your PRTG system that can affect the quality of the monitoring results:

  • Health: This index value sums up the probe state into a value between 100% (healthy) and 0% (failing). Frequent or repeated health values below 100% should be investigated.
  • Available Memory: This channel shows the amount of free memory available on the system. This value should not fall below 500 MB. This way, PRTG can still request resources during report generation, auto-discoveries, and other issues.
  • Available Memory Percent: This channel shows the free memory available on the system in percent.
  • System CPU Load: This channel shows the current percentage CPU load on the system with the probe. Extensive CPU load can lead to false, incomplete, and incorrect monitoring results. This value should usually stay below 50%.
System Health Sensor
System Health Sensor

Sensor in Other Languages

Dutch: System Status, French: État du système, German: Systemzustand, Japanese: システムヘルス, Portuguese: Funcionamento do sistema, Russian: Работоспособность системы, Simplified Chinese: 系统健康状况, Spanish: Salud del sistema

Sensor Settings

On the details page of a sensor, click the Settings tab to change its settings.

icon-i-roundUsually, a sensor connects to the IP Address or DNS Name of the parent device where you created this sensor. See the Device Settings for details. For some sensor types, you can define the monitoring target explicitly in the sensor settings. Please see below for details on available settings.

Basic Sensor Settings

Sensor Name

Enter a meaningful name to identify the sensor. By default, PRTG shows this name in the device tree, as well as in alarms, logs, notifications, reports, maps, libraries, and tickets.

Parent Tags

Shows Tags that this sensor inherits from its parent device, group, and probe. This setting is shown for your information only and cannot be changed here.

Tags

Enter one or more Tags, separated by spaces or commas. You can use tags to group sensors and use tag–filtered views later on. Tags are not case sensitive. We recommend that you use the default value.

You can add additional tags to the sensor if you like. Other tags are automatically inherited from objects further up in the device tree. These are visible above as Parent Tags.

icon-i-roundIt is not possible to enter tags with a leading plus (+) or minus (-) sign, nor tags with round parentheses (()) or angle brackets (<>).

Priority

Select a priority for the sensor. This setting determines where the sensor is placed in sensor lists. Top priority is at the top of a list. Choose from one star (low priority) to five stars (top priority).

Sensor Display

Primary Channel

Select a channel from the list to define it as the primary channel. In the device tree, the last value of the primary channel will always be displayed below the sensor's name. The available options depend on what channels are available for this sensor.

icon-i-roundYou can set another primary channel later by clicking the pin symbol of a channel in the sensor's Overview tab.

Graph Type

Define how different channels will be shown for this sensor.

  • Show channels independently (default): Show an own graph for each channel.
  • Stack channels on top of each other: Stack channels on top of each other to create a multi-channel graph. This will generate an easy-to-read graph that visualizes the different components of your total traffic.
    icon-i-roundThis option cannot be used in combination with manual Vertical Axis Scaling (available in the Sensor Channels Settings settings).

Stack Unit

This setting is only available if stacked graphs are selected above. Choose a unit from the list. All channels with this unit will be stacked on top of each other. By default, you cannot exclude single channels from stacking if they use the selected unit. However, there is an advanced procedure to do so.

Inherited Settings

By default, all following settings are inherited from objects higher in the hierarchy and should be changed there, if necessary. Often, best practice is to change them centrally in the Root group's settings, see section Inheritance of Settings for more information. To change a setting only for this object, disable inheritance by clicking the button next to inherit from under the corresponding setting name. You will then see the options described below.

Scanning Interval

Click inherited_settings_button to disrupt the inheritance. See section Inheritance of Settings for more information.

Scanning Interval

Select a scanning interval (seconds, minutes, or hours) from the list. The scanning interval determines the time the sensor waits between two scans. You can change the available intervals in the system administration on PRTG on premises installations.

If a Sensor Query Fails

Define the number of scanning intervals that a sensor has time to reach and check a device again in case a sensor query fails. The sensor can try to re-reach and check a device several times, depending on the option you select here, before it will be set to a Down status. This helps you avoid false alarms if the monitored device has only temporary issues. For previous scanning intervals with failed requests, the sensor will show a Warning status. Choose between:

  • Set sensor to "down" immediately: The sensor will show an error immediately after the first failed request.
  • Set sensor to "warning" for 1 interval, then set to "down" (recommended): After the first failed request, the sensor will show a yellow warning status. If the following request also fails, the sensor will show an error.
  • Set sensor to "warning" for 2 intervals, then set to "down": Show an error status only after three consecutively failed requests.
  • Set sensor to "warning" for 3 intervals, then set to "down": Show an error status only after four consecutively failed requests.
  • Set sensor to "warning" for 4 intervals, then set to "down": Show an error status only after five consecutively failed requests.
  • Set sensor to "warning" for 5 intervals, then set to "down": Show an error status only after six consecutively failed requests.

icon-i-roundSensors that monitor via Windows Management Instrumentation (WMI) always wait at least one scanning interval until they show an error. It is not possible to set a WMI sensor to "down" immediately, so the first option will not apply to these sensor types. All other options can apply.

icon-i-roundIf a sensor has defined error limits for channels, it will always show a Down status immediately, so no "wait" option will apply.
 

icon-i-roundIf a channel uses lookup values, it will always show a Down status immediately, so no "wait" options will apply.

Access Rights

Click inherited_settings_button to disrupt the inheritance. See section Inheritance of Settings for more information.

User Group Access

Define which user group(s) will have access to the object you're editing. A table with user groups and types of access rights is shown: It contains all user groups from your setup. For each user group, you can choose from the following access rights:

  • Inherited: Use the access rights settings of the parent object.
  • None: Users in this group cannot see or edit the object. The object neither shows up in lists nor in the device tree. Exception: If a child object is visible to the user, the object is visible in the device tree, though not accessible.
  • Read: Users in this group can see the object and review its monitoring results.
  • Write: Users in this group can see the object, review its monitoring results, and edit the object's settings. They cannot edit access rights settings.
  • Full: Users in this group can see the object, review its monitoring results, edit the object's settings, and edit access rights settings.

You can create new user groups in the System Administration—User Groups settings. To automatically set all objects further down in the hierarchy to inherit this object's access rights, set a check mark for the Revert children's access rights to inherited option.

icon-book-arrowsFor more details on access rights, see the section User Access Rights.

Channel Unit Configuration

Click inherited_settings_button to disrupt the inheritance. See section Inheritance of Settings for more information.

Channel Unit Types

For each type of sensor channel, define the unit in which data is displayed. If defined on probe, group, or device level, these settings can be inherited to all sensors underneath. You can set units for the following channel types (if available):

  • Bandwidth
  • Memory
  • Disk
  • File
  • Custom

icon-i-roundCustom channel types can be set on sensor level only.

Edit Sensor Channels

To change display settings, spike filter, and limits, switch to the sensor's Overview tab and click the gear icon of a specific channel. For detailed information, see the Sensor Channels Settings section.

Notifications

Click the Notifications tab to change notification triggers. For detailed information, see the Sensor Notifications Settings section.

Others

For more general information about settings, see the Object Settings section.

Sensor Settings Overview

For information about sensor settings, see the following sections: