PRTG Manual: SNMP Linux Disk Free v2 Sensor

Management Information Base

This sensor uses data found in the UCD-DISKIO Management Information Base (MIB) module.

IPv6

This sensor supports IPv6.

Scanning interval

This sensor has a fixed minimum scanning interval for performance reasons. You cannot use a shorter scanning interval. Consequently, shorter scanning intervals in the Monitoring settings are not available for this sensor.

• The minimum scanning interval of this sensor is 1 minute.
• The recommended scanning interval of this sensor is 1 minute.

Performance impact

This sensor has a very low performance impact.

Multi-platform probe

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

Knowledge Base

• Knowledge Base: Why do SSH Disk Free and SNMP Linux Disk Free show different values for my target Linux system?
• Knowledge Base: Which encryption algorithms do PRTG SSH sensors support?

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 (GiB)

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

Specify an upper limit in gibibytes. 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 (GiB)

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

Specify an upper limit in gibibytes. 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 (GiB)

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

Specify a lower limit in gibibytes. 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 Error Limit (GiB)

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

Specify a lower limit in gibibytes. 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.

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 Bytes [Mounted Partition]

The free space

Free INodes % [Mounted Partition]

The free index nodes (%)

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

Total Free Bytes

The total free disk space. This sensor only calculates the free space of physical disks.

This channel is the primary channel by default.