PRTG Manual: SSH Disk Free v2 Sensor

Credentials

This sensor requires credentials for Linux/Solaris/macOS (SSH/WBEM) systems in the settings of the parent device.

Distributions

This sensor does not support all Linux/Unix and macOS distributions.

Add Sensor dialog

You can select up to 100 disks in the Add Sensor dialog. If you select more disks, you cannot create the sensor. Add the sensor multiple times to monitor more than 100 disks with several sensors.

IPv6

This sensor supports IPv6.

Multi-platform probe

You can add this sensor to a multi-platform probe.

Limits

This sensor has predefined limits for one or several metrics.

Performance impact

This sensor has a low performance impact.

Knowledge Base

• Knowledge Base: Which encryption algorithms do PRTG SSH sensors support?
• Knowledge Base: SSH and SFTP sensors in Unknown status

Disk

Shows the mount point of a disk that this sensor monitors.

PRTG shows this value for reference purposes only. We strongly recommend that you only change it if the Paessler support team explicitly asks you to do so. Wrong usage can result in incorrect monitoring data.

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. The maximum timeout value is 300 seconds (5 minutes). The default timeout value is 10 seconds. 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). The default timeout value is 10 seconds. 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 Inheritance

Define which port this sensor uses for the SSH connection:

• Inherit port from parent device (default): Use the port number as defined in the Credentials for Linux/Solaris/macOS (SSH/WBEM) Systems section of the parent device settings.
• Do not inherit port (enter a custom SSH port): Define a custom port number below and do not use the port number from the parent device settings.

Custom SSH Port

This setting is only visible if you select Do not inherit port (enter a custom SSH port) above.

Enter the port number (between 1 and 65535) that this sensor uses for the SSH connection. The default port number is 22. Enter an integer.

Percentage Limit Check

This setting is only visible during sensor creation. If you want to change this setting after sensor creation, use the channel settings.

By default, the sensor enables percentage limits with a lower warning limit and a lower error limit. Enable or disable a limit check for the free space in percentage channels of all drives:

• Use default limits: Use the default lower limits. The default lower warning limit is 25%. The default lower error limit is 10%.
• Use custom limits: Define sensor limits that are valid for all percentage channels. Additional fields appear below. The sensor shows the Warning or the Down status when free space limits are above or below the limits.

Upper Error Limit

This setting is only visible if you select Use custom limits above.

Specify an upper limit in percent for the Down status. If the free disk space of one of your drives exceeds this value, the sensor changes to the Down status. Enter an integer or leave the field empty.

Upper Warning Limit

This setting is only visible if you select Use custom limits above.

Specify an upper limit in percent for the Warning status. If the free disk space of one of your drives exceeds this value, the sensor changes to the Warning status. Enter an integer or leave the field empty.

Lower Warning Limit

This setting is only visible if you select Use custom limits above.

Specify a lower limit in percent for the Warning status. If the free disk space of one of your drives falls below this value, the sensor changes to the Warning status. Enter an integer or leave the field empty.

Lower Error Limit

This setting is only visible if you select Use custom limits above.

Specify a lower limit in percent for the Down status. If the free disk space of one of your drives falls below this value, the sensor changes to the Down status. Enter an integer or leave the field empty.

Size Limit Check

This setting is only visible during sensor creation. If you want to change this setting after sensor creation, use the channel settings.

Enable or disable a limit check for the free bytes channels of all drives:

• Do not use size limits (default): Do not define sensor limits that are valid for all byte size channels. The sensor only uses limits that you define in the settings of the particular free space in bytes channels to determine the status.
• Use size limits: Define limits for the sensor that are valid for all byte size channels. Additional fields appear below. The sensor shows the Warning or Down status when free space limits are above or below the value.

By default, byte size limits are not enabled for drives.

Upper Error Limit

This setting is only visible if you select Use size limits above.

Specify an upper limit. Use the same unit as shown by the free bytes channels of this sensor (the default unit is MB). If the free disk space of one of your drives exceeds this value, the sensor changes to the Down status. Enter an integer or leave the field empty.

Upper Warning Limit

This setting is only visible if you select Use size limits above.

Specify an upper limit. Use the same unit as shown by the free bytes channels of this sensor (the default unit is MB). If the free disk space of one of your drives exceeds this value, the sensor changes to the Warning status. Enter an integer or leave the field empty.

Lower Warning Limit

This setting is only visible if you select Use size limits above.

Specify a lower limit. Use the same unit as shown by the free bytes channels of this sensor (the default unit is MB). If the free disk space of one of your drives falls below this value, the sensor changes to the Warning status. Enter an integer or leave the field empty.

Lower Error Limit

This setting is only visible if you select Use size limits above.

Specify a lower limit. Use the same unit as shown by the free bytes channels of this sensor (the default unit is MB). If the free disk space of one of your drives falls below this value, the sensor changes to the Down status. Enter an integer or leave the field empty.

Alarm on Missing/Removed Disk

If a monitored disk is removed or not found, the sensor sets the values to zero. Select the alarm approach in this case:

• Deactivate alarm (default): Do not send an alert for a removed disk.
• Activate alarm: Send an alert if a monitored disk is removed or not found.

Primary Channel

Select a channel from the list to define it as the primary channel. In the device tree, PRTG displays the last value of the primary channel 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 this sensor shows different channels:

• 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. PRTG stacks all channels with this unit 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.

Result Handling

Define what PRTG does with the sensor result:

• Discard result (default): Do not store the sensor result.
• Store result: Store the sensor result and the last response in the \Logs\sensors subfolder of the PRTG data directory on the probe system. The file name is Result of Sensor [ID].log. This setting is for debugging purposes. PRTG overwrites this file with each scanning interval.

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.

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.

Free Space % [Mounted Partition]

The free space (%)

This channel has default limits defined by the Global Disk Limits in the sensor settings.

• Lower error limit: 10
• Lower warning limit: 25

Free Space [Mounted Partition]

The free space

Total Free Space

The total free space

This channel is the primary channel by default.