Inaccessible virtual machines are named as Unknown VM

Products

• VMware vCenter Server

Issue/Introduction

Virtual machines are shown in vCenter Server as Unknown VM.

Environment

VMware vCenter Server 6.x

VMware vCenter Server 7.x

VMware vCenter Server 8.x

Cause

When an ESXi/ESX host is rebooted or a host agent is restarted, it needs to reload the host agent configuration of each registered virtual machine (.vmx file). If the .vmx file is inaccessible, the ESXi/ESX host is unable to read the configured name of the virtual machine, and it defaults to Unknown VM.

Resolution

Temporarily losing access to storage does not cause a virtual machine's name to be permanently set to Unknown VM. For more information, see Identifying Fibre Channel, iSCSI, and NFS storage issues on ESX/ESXi hosts (309348).

 

After the storage problems are addressed, restart the management agents on the host. For more information, see Restarting the Management agents on an ESXi or ESX host (320280).

 

If the virtual machine still shows as Unknown VM, examine the /etc/vmware/hostd/vmInventory.xml file on the host to see which virtual machines were registered. Make a note of the virtual machines and the datastores on which they are located, then re-register those virtual machines.

 

To re-register a virtual machine:

1. Right-click the Unknown VM entry and choose Remove From Inventory
2. Browse to the appropriate datastore for the virtual machine and open the folder
3. Right-click the *.vmx file and choose Add to Inventory
4. Power on the virtual machine
5. Repeat Steps 1 to 4 for all Unknown VM virtual machines