This sensor can show raw data from performance counters that monitor hard or fixed disk drives on a computer. For this purpose, this sensor type uses a hybrid approach, first trying to query data via Windows Performance Counters (which needs less system resources), and using WMI as a fallback in case performance counters are not available. In previous PRTG versions, this sensor used WMI only and was called WMI Physical Disk Sensor.
Disks are used to store file, program, and paging data and are read to retrieve these items, and written to record changes to them. The values of physical disk counters are sums of the values of the logical disks, or partitions, into which they are divided.
Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.