Network Management

Volume status is Unknown on Virtual Machines (VMs) or drives volume serial number has changed in the SolarWinds Platform

This article discusses a behavior in the SolarWinds Platform (NPM) where volume status on a virtual machine will show as unknown and a new volume object or volume serial number (VSN) of the same drive name will appear on List Resources.

First published date

11/6/2018 10:37 PM

Last published date

12/22/2025 11:39 PM

Overview

When monitoring volumes hosted on virtual machines, you may notice their status will eventually go unknown. A new volume object or drive volume serial number (VSN) with the same drive name will appear under "List Resources."

Product section

Network Performance Monitor

Cause

Windows assigns a volume serial number to every volume (for example, C:\ Label: 78b5bb82). If the virtual machine disk (VMDK) gets a full VMWare version, the administrator may change the size of the VMDK. Windows interprets it as a new volume and assigns a new volume serial number when this happens. NPM uses the serial number from the VolumeDesc SNMP result to map drives in SNMP also via WMI, so if the serial number changes, NPM also sees it as a new drive. It can cause the old drive to become "orphaned" because it no longer exists on that host.

Resolution

  • Remove the old drive and add the new drive via List Resources.
  • SolarWinds recommends VMWare administrators notify the NPM administrator when the VMDK size is changed.

It is also possible that the environment has a configuration or script that automatically allocates or manages volumes on the environment that causes the volumes to be removed.