The page below is from the manual of PRTG, our quick-to-install and easy-to-use network monitoring software

Try PRTG now and see how it can make your job easier.
 

Free Trial Download
You will be up and running in 2 minutes
Learn More
Screenshots, Features, Videos


Aurelio, System Admin at Paessler AG

The SSH Load Average sensor monitors the load average of a Linux/Unix system using Secure Shell (SSH).

It shows the following:

  • Average system load within a 1-minute interval
  • Average system load within a 5-minute interval
  • Average system load within a 15-minute interval
     
SSH Load Average SensorSSH Load Average Sensor

Click here to enlarge: http://media.paessler.com/prtg-screenshots/ssh_load_average.png

Remarks

  • For this sensor type you must define credentials for Linux/Solaris/Mac OS (SSH/WBEM) systems on the device you want to use the sensor on.
  • This sensor type cannot support all Linux/Unix and Mac OS distributions.
  • For a general introduction to SSH monitoring, please see manual section Monitoring via SSH .

Add Sensor

The Add Sensor dialog appears when you manually add a new sensor to a device. It only shows the setting fields that are required for creating the sensor. Therefore, you will not see all setting fields in this dialog. You can change (nearly) all settings in the sensor's Settings tab later.

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 .

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).

SSH Specific

Connection Timeout (Sec.)

Define a timeout in seconds for the connection. This is the time the sensor will wait to establish a connection to the host. Keep this value as low as possible. The maximum value is 900 seconds (15 minutes). Please enter an integer value.

Shell Timeout (Sec.)

Define a timeout in seconds for the shell response. This is the time in seconds the sensor will wait 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). Please enter an integer value.

SSH Port

Define which port this sensor uses for the SSH connection. Choose between:

  • Inherit port number from parent device (default) : Use the port number as defined in the Credentials for Linux/Solaris/Mac OS (SSH/WBEM) Systems section of the device this sensor is created on.
  • Enter custom port number : Define a custom port number below and do not use the port number from the parent device settings.

Use Port Number

This field is only visible if you choose Enter custom port number above. Enter the port number (between 1 and 65535) that this sensor will use for the SSH connection. Please enter an integer value.

SSH Engine

Select the method you want to use to access data with this SSH sensor. We strongly recommend that you use the default engine! For some time you still can use the legacy mode to ensure compatibility with your target systems. Choose between:

  • Inherit from parent device (default) : Use the SSH engine that you have defined in the parent device settings or higher in the object hierarchy. If you did not change it, this is the recommended default engine.
  • Default : This is the default monitoring method for SSH sensors. It provides best performance and security. It is set by default in objects that are higher in the hierarchy so usually you can keep the Inherit from parent device (default) option.
  • Compatibility Mode (deprecated) : Try this legacy method only if the default mode does not work on a target device. The compatibility mode is the SSH engine that PRTG used in previous versions and is deprecated. We will remove this legacy option soon, so please try to get your SSH sensors running with the default SSH engine.

icon-i-round-redThe option you select here overrides the selection of the SSH engine in a higher object (which is a parent device, group, probe, or root).

Result Handling

Define what PRTG will do with the sensor results. Choose between:

  • Discard sensor result : Do not store the sensor result.
  • Write sensor result to disk (Filename: "Result of Sensor [ID].txt") : Store the last result received from the sensor to the Logs (Sensor) directory (on the Master node, if in a cluster). File names: Result of Sensor [ID].txt and Result of Sensor [ID].Data.txt . This is for debugging purposes. PRTG overrides these files with each scanning interval. For more information on how to find the folder used for storage, please see the Data Storage section.

icon-prtg-on-demandYou cannot access stored sensor logs on PRTG on demand.

  • Write sensor result to disk (Filename: "Result of Sensor [ID].txt")  in case of error : Store the last result of the sensor only if it throws an error.

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. To change a setting only for this object, disable inheritance by clicking the check mark in front of the corresponding setting name. You will then see the options described below.

Scanning Interval

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 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 continuously failed requests.
  • Set sensor to "warning" for 3 intervals, then set to "down" : Show an error status only after four continuously failed requests.
  • Set sensor to "warning" for 4 intervals, then set to "down" : Show an error status only after five continuously failed requests.
  • Set sensor to "warning" for 5 intervals, then set to "down" : Show an error status only after six continuously 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.

Schedules, Dependencies, and Maintenance Window

icon-i-roundInheritance for schedules, dependencies, and maintenance windows cannot be interrupted. The corresponding settings from the parent objects will always be active. However, you can define additional settings here. They will be active at the same time as the parent objects' settings.

Schedule

Select a schedule from the list. Schedules can be used to monitor for a certain time span (days, hours) every week. With the period list option it is also possible to pause monitoring for a specific time span. You can create new schedules and edit existing ones in the account settings.

icon-i-roundSchedules are generally inherited. New schedules will be added to existing ones, so all schedules are active at the same time.

Maintenance Window

Specify if you want to set up a one-time maintenance window. During a "maintenance window" period, this object and all child objects will not be monitored. They will be in a paused state instead. Choose between:

  • Not set (monitor continuously) : No maintenance window will be set and monitoring will always be active.
  • Set up a one-time maintenance window : Pause monitoring within a maintenance window. You can define a time span for a monitoring pause below and change it even for a currently running maintenance window.

icon-i-roundTo terminate a current maintenance window before the defined end date, change the time entry in Maintenance Ends field to a date in the past.

Maintenance Begins

This field is only visible if you enabled the maintenance window above. Use the date time picker to enter the start date and time of the maintenance window.

Maintenance Ends

This field is only visible if you enabled the maintenance window above. Use the date time picker to enter the end date and time of the maintenance window.

Dependency Type

Define a dependency type. Dependencies can be used to pause monitoring for an object depending on the status of another. You can choose between:

  • Use parent : Pause the current sensor if the device, where it is created on, is in Down status, or is paused by another dependency.
  • Select object : Pause the current sensor if the device, where it is created on, is in Down status, or is paused by another dependency. Additionally, pause the current sensor if a specific other object in the device tree is in Down status, or is paused by another dependency. Select below.
  • Master object for parent : Make this sensor the master object for its parent device. The sensor will influence the behavior of the device, where it is created on: If the sensor is in Down status, the device will be paused. For example, it is a good idea to make a Ping sensor the master object for its parent device to pause monitoring for all other sensors on the device in case the device cannot even be pinged. Additionally, the sensor will be paused if the parent group of its parent device is in Down status, or if it is paused by another dependency.

icon-i-roundTesting your dependencies is easy! Simply choose Simulate Error Status from the context menu of an object that other objects depend on. A few seconds later all dependent objects should be paused. You can check all dependencies in your PRTG installation by selecting Devices | Dependencies from the main menu bar.

Dependency

This field is only visible if the Select object option is enabled above. Click on the reading-glasses and use the object selector to choose an object on which the current sensor will depend.

Dependency Delay (Sec.)

Define a time span in seconds for a dependency delay. After the master object for this dependency goes back to Up status, PRTG will start monitoring the depending objects after this extra delayed. This can help to avoid false alarms, for example, after a server restart, by giving systems more time for all services to start up. Please enter an integer value.

icon-i-round-redThis setting is not available if you choose this sensor to Use parent or to be the Master object for parent . In this case, please define delays in the parent Device Settings or in the superior Group Settings .

Access Rights

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.

For more details on access rights, please see the section User Access Rights .

Channel Unit Configuration

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.

More

Knowledge Base: How and Where Does PRTG Store its Data?

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, please see the Sensor Channels Settings section.

Notifications

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

Others

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

Sensor Settings Overview

Feedback / Questions
Copyright © 1998 - 2017 Paessler AG