<%NUMBERING1%>.<%NUMBERING2%>.<%NUMBERING3%> PRTG Manual: WMI Logical Disk I/O Sensor

The WMI Logical Disk I/O sensor monitors the disk usage of a logical disk or mount point on a Windows system via Windows Management Instrumentation (WMI).

i_round_blueThe sensor shows performance data of counters that monitor logical partitions of a hard drive. The system monitor identifies logical disk instances by their identifier, such as C, and the sensor reads the logical disk object in the system monitor and returns the values.

WMI Logical Disk I/O Sensor

WMI Logical Disk I/O Sensor

i_square_cyanFor a detailed list and descriptions of the channels that this sensor can show, see section Channel List.

Sensor in Other Languages

  • Dutch: WMI Logische Schijf I/O
  • French: Disque logique E/S (WMI)
  • German: WMI Logischer Datenträger E/A
  • Japanese: WMI 論理ディスク I/O
  • Portuguese: E/S do disco lógico (WMI)
  • Russian: Ввод-вывод логического диска WMI
  • Simplified Chinese: WMI 逻辑磁盘 I/O
  • Spanish: E/S de disco lógico (WMI)


Consider the following remarks and requirements for this sensor:



Performance impact

  • This sensor has a high performance impact. Stay below 200 WMI sensors per probe. Above this number, consider using multiple remote probes for load balancing.


  • This sensor requires WoW64 (Windows 32-bit on Windows 64-bit) for target systems that run Windows Server 2016.

Windows version

  • This sensor requires at least Windows Server 2008 R2. It does not work on previous Windows versions (Windows Server 2008 or earlier).


  • This sensor requires credentials for Windows systems.


  • This sensor supports IPv6.

Hosted probe

i_podYou cannot add this sensor to the hosted probe of a PRTG Hosted Monitor instance. If you want to use this sensor, add it to a remote probe device.

Basic Sensor Settings

Basic Sensor Settings

Basic Sensor Settings

The sensor has the following default tags that are automatically predefined in the sensor's settings when you add the sensor:

  • wmilogicalsensor

i_square_cyanFor more information about basic sensor settings, see section Sensor Settings.

WMI Logical Disk I/O Specific

WMI Logical Disk I/O Specific

WMI Logical Disk I/O Specific




The logical disk or mount point that this sensor monitors.

Debug Options

Debug Options

Debug Options



Result Handling

Define what PRTG does with the sensor result:

  • Discard result (default): 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 and Result of Sensor [ID].Data.txt. This setting is for debugging purposes. PRTG overwrites these files with each scanning interval.

i_round_blueIn a cluster, PRTG stores the result in the PRTG data directory of the master node.

Sensor Display

Sensor Display

Sensor Display



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.

i_round_blueYou can set a different primary channel later by clicking b_channel_primary 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.
    i_round_redYou 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.

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 b_inherited_enabled under the corresponding setting name to disable the inheritance and to display its options.

i_square_cyanFor more information, see section Inheritance of Settings.

Channel List

i_round_blueWhich channels the sensor actually shows might depend on the target device, the available components, and the sensor setup.



Avg. Bytes Per Read

The average number of bytes per read

Avg. Bytes Per Transfer

The average number of bytes per transfer

Avg. Bytes Per Write

The average number of bytes per write

Avg. Queue Length

The average number of items in the queue

Avg. Read Queue

The average number of items in the read queue

Avg. Read Time

The average read time

Avg. Transfer Time

The average transfer time

Avg. Write Queue

The average number of items in the write queue

Avg. Write Time

The average write time

Current Queue

The current number of items in the queue

Disk IOs

The number of disk I/O operations

Disk Read

The disk read speed

Disk Read IOs

The number of disk read I/O operations

Disk Read Time %

The disk read time (%)

Disk Time %

The disk time (%)

Disk Transfer

The disk transfer speed

Disk Write

The disk write speed

Disk Write IOs

The number of disk write I/O operations

Disk Write Time %

The disk write time (%)


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

The free space

Free Space %

The free space (%)

i_round_blueThis channel is the primary channel by default.

Idle Time %

The idle time (%)

Split IOs

The number of split I/O operations


i_square_blueKNOWLEDGE BASE

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My WMI sensors don't work. What can I do?