The SSH Script sensor connects to a Linux/Unix system via Secure Shell (SSH) and executes a script file that is located on the target system. This option is available as part of the PRTG API.
SSH Script Sensor
For a detailed list and descriptions of the channels that this sensor can show, see section Channel List.
Sensor in Other Languages
Dutch: SSH Script
French: Script (SSH)
German: SSH-Skript
Japanese: SSH スクリプト
Portuguese: Script (SSH)
Russian: Скрипт SSH
Simplified Chinese: SSH 脚本
Spanish: Script (SSH)
Remarks
This sensor has a very high performance impact. We recommend that you use no more than 50 of this sensor on each probe.
For security reasons, this sensor requires that you store your script file in the /var/prtg/scripts directory on the target system. Make sure that the script has executable rights. If the script is not available or was deleted from the directory, you get the error message Script not found (237).
This sensor requires credentials for Linux/Solaris/macOS (SSH/WBEM) systems in the settings of the parent device.
This sensor does not support all Linux/Unix and macOS distributions.
This sensor only supports IPv4.
For more information about the return value format, see the PRTG Manual Custom Sensors.
If the name contains angle brackets (<>), PRTG replaces them with braces ({}) for security reasons. For more information, see the Knowledge Base: What security features does PRTG include?
This setting is for your information only. You cannot change it.
Tags
Enter one or more tags. Confirm each tag with the Spacebar key, a comma, or the Enter key. You can use tags to group objects and use tag-filtered views later on. Tags are not case-sensitive. Tags are automatically inherited.
It is not possible to enter tags with a leading plus (+) or minus (-) sign, nor tags with parentheses (()) or angle brackets (<>).
For performance reasons, it can take some minutes until you can filter for new tags that you added.
The sensor has the following default tags that are automatically predefined in the sensor's settings when you add the sensor:
sshscript
Priority
Select a priority for the sensor. This setting determines the position of the sensor in lists. The highest priority is at the top of a list. Choose from the lowest priority () to the highest priority ().
Enter a description for Placeholder 1, for example information about the purpose or content of the placeholder.
Placeholder 1
Enter a value for the placeholder. PRTG inserts the value for the script execution if you add %scriptplaceholder1 in the argument list. PRTG does not display the value in the sensor log or the sensor's settings.
Placeholder 2 Description
Enter a description for Placeholder 2, for example information about the purpose or content of the placeholder.
Placeholder 2
Enter a value for the placeholder. PRTG inserts the value for the script execution if you add %scriptplaceholder2 in the argument list. PRTG does not display the value in the sensor log or the sensor's settings.
Placeholder 3 Description
Enter a description for Placeholder 3, for example information about the purpose or content of the placeholder.
Placeholder 3
Enter a value for the placeholder. PRTG inserts the value for the script execution if you add %scriptplaceholder3 in the argument list. PRTG does not display the value in the sensor log or the sensor's settings.
Placeholder 4 Description
Enter a description for Placeholder 4, for example information about the purpose or content of the placeholder.
Placeholder 4
Enter a value for the placeholder. PRTG inserts the value for the script execution if you add %scriptplaceholder4 in the argument list. PRTG does not display the value in the sensor log or the sensor's settings.
Placeholder 5 Description
Enter a description for Placeholder 5, for example information about the purpose or content of the placeholder.
Placeholder 5
Enter a value for the placeholder. PRTG inserts the value for the script execution if you add %scriptplaceholder5 in the argument list. PRTG does not display the value in the sensor log or the sensor's settings.
Sensor Settings
Sensor Settings
Setting
Description
Script
Select a script file from the dropdown list. It shows all script files that are available in the /var/prtg/scripts directory on the target Linux/Unix system. For a script file to appear in this list, store the target file in this directory.
Make sure that the script has executable rights.
To show the expected sensor value and status, your file must use the correct format for the returned values. In this case, it is exitcode:value:message to standard output stdout. The exit code determines the sensor status.
For detailed information on how to create custom sensors and for the return format, see section Custom Sensors.
In SSH scripts, you can use alphanumeric characters and the special characters ".", "_", "-", "=", and "/" outside of quoted strings.
Mutex Name
Define a mutual exclusion (mutex) name for the process. Enter a string or leave the field empty.
PRTG runs all custom script sensors that have the same mutex name serially (not simultaneously). This is useful if you use a lot of sensors and want to avoid high resource usage caused by processes that run running at the same time.
Define a unit for the channel value. Enter a string. This is for display purposes only and is the default unit for a new channel. You can change the unit after sensor creation in the sensor's channel settings.
Value Type
Define the type of the values that your executable or script file returns:
Integer: An integer is expected as return value. If the script returns a float, PRTG displays the value 0.
Float: A float is expected as return value, with a dot (.) between the predecimal position and the decimal places. The sensor also displays integers unless they produce a buffer overflow.
Counter: Your script returns an integer that increases. PRTG shows the difference between the values of two sensor scans. A counter must return an integer. It does not support float values.
The sensor does not support string values.
You cannot change this value after sensor creation.
If Value Changes
Define what the sensor does when its value changes:
Ignore (default): Do nothing.
Trigger 'change' notification: Send an internal message that indicates a change. In combination with a change trigger, you can use this to trigger a notification if a change occurs.
SSH Specific
SSH Specific
Setting
Description
Connection Timeout (Sec.)
Define a timeout in seconds for the connection. This is the time that the sensor waits to establish a connection to the host. Keep this value as low as possible. Enter an integer.
Make sure that the connection timeout is a value that is higher than the shell timeout to avoid potential errors.
Shell Timeout (Sec.)
Define a timeout in seconds for the shell response. This is the time in seconds the sensor waits for the shell to return a response after it has sent its specific command (for example, cat /proc/loadavg). The maximum value is 300 seconds (5 minutes). Enter an integer.
Make sure that the shell timeout is a value that is lower than the connection timeout to avoid potential errors.
SSH Port
Define which port this sensor uses for the SSH connection:
Inherit from parent device (default): Use the SSH engine that you defined in the parent device settings or higher up in the object hierarchy. If you have not changed the SSH engine, this is the recommended option.
Default: This is the default SSH engine. It provides the best performance and security. It is set by default in objects that are higher up in the hierarchy, so usually you can keep the Inherit from parent device (default) option.
Compatibility mode (deprecated): Use this only if the default SSH engine does not work on a target device. The compatibility mode is the SSH engine that PRTG used in previous versions. It is deprecated. We will remove this legacy mode soon, so try to get your SSH sensors to run with the default SSH engine.
We strongly recommend that you use the default SSH engine.
The option you select here overrides the selection of the SSH engine in a higher object: a parent device, group, probe, or root.
Result Handling
Define what PRTG does with the sensor result:
Discard result: Do not store the sensor result.
Store result: Store the last sensor result in the \Logs\sensors subfolder of the PRTG data directory on the probe system. The file names are Result of Sensor [ID].txt, Result of Sensor [ID].Data.txt, and Result of Sensor [ID] (SSHv2).txt. This setting is for debugging purposes. PRTG overwrites these files with each scanning interval.
Store result in case of error: Store the last sensor result only if the sensor shows the Down status.
This option is not available when the sensor runs on the hosted probe of a PRTG Hosted Monitor instance.
In a cluster, PRTG stores the result in the PRTG data directory of the master node.
Sensor Display
Sensor Display
Setting
Description
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 is always displayed below the sensor's name. The available options depend on what channels are available for this sensor.
You can set a different primary channel later by clicking below a channel gauge on the sensor's Overview tab.
Graph Type
Define how different channels are shown for this sensor:
Show channels independently (default): Show a 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 generates a graph that visualizes the different components of your total traffic. You cannot use this option in combination with manual Vertical Axis Scaling (available in the channel settings).
Stack Unit
This setting is only visible if you select Stack channels on top of each other above.
Select a unit from the list. All channels with this unit are 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 of these settings are inherited from objects that are higher in the hierarchy. We recommend that you change them centrally in the root group settings if necessary. To change a setting for this object only, click under the corresponding setting name to disable the inheritance and to display its options.
For more information, see section Root Group Settings, section Scanning Interval.
Schedules, Dependencies, and Maintenance Window
You cannot interrupt the inheritance for schedules, dependencies, and maintenance windows. The corresponding settings from the parent objects are always active. However, you can define additional schedules, dependencies, and maintenance windows. They are active at the same time as the parent objects' settings.
Schedules, Dependencies, and Maintenance Window
For more information, see section Root Group Settings, section Schedules, Dependencies, and Maintenance Window.
Access Rights
Access Rights
For more information, see section Root Group Settings, section Access Rights.
Channel Unit Configuration
Which channel units are available depends on the sensor type and the available parameters. If no configurable channels are available, this field shows No configurable channels.
Channel Unit Configuration
For more information, see section Root Group Settings, section Channel Unit Configuration.
Channel List
Which channels the sensor actually shows might depend on the target device, the available components, and the sensor setup.
Channel
Description
Downtime
In the channel table on the Overview tab, this channel never shows any values. PRTG uses this channel in graphs and reports to show the amount of time in which the sensor was in the Down status
Execution Time
The execution time
This channel is the primary channel by default.
[Value]
The value that the script file returns in one channel
For details about the return value format, see section Custom Sensors.
More
KNOWLEDGE BASE
Which encryption algorithms do PRTG SSH sensors support?