Powering ON a VM on vSAN fails with error: "Unable to enumerate all disks. A required file was not found"

Products

• VMware vSAN

Issue/Introduction

Symptoms:

• Error when trying to power ON the VM running on snapshot: "Unable to enumerate all disks. A required file was not found" 

  

• Following message is seen on the VM summary tab: "Some of the disks of the virtual machine failed to load. The information present for them in the virtual machine configuration may be incomplete"
  
  

• The hard disk shows 0 MB under edit settings of the VM:

  

Environment

VMware vSAN (All Versions)

Cause

•  The VM's base disk descriptor file (.vmdk) is missing from the VM folder due to which the VM fails to power ON.

• This can be verified using the command to list the VM's vSAN objects: esxcli vsan debug object list --all | less

  Path: /vmfs/volumes/vsan:########/########/###.vmdk (Missing)
  Group UUID: ####
  Directory Name: N/A

Resolution

To resolve the issue, follow the below steps:

• Create the descriptor file:

  1. Command: cmmds-tool find -t DOM_OBJECT -f json -u <UUID>

     Copy the "addressSpace" details from the output.

  2. Command to create a descriptor file: vmkfstools -c <addressSpace> VM_name.vmdk

  3. Command to create a backup of the vmdk which can be deleted later: cp VM_name.vmdk VM_name.vmdk.bak

• Execute the below steps:

  1. Check the snapshot file details and note the parentCID: cat VM_name-snapshot.vmdk

     parentCID="###"

  2. Command to fetch the UUID and path of the virtual object (.vmdk): esxcli vsan debug object list --all  |less 

     Output:

     Object UUID:"###"

  3. Change the CID and path UUID on the base disk file from the output in step 1 and step 2: vi VM_name.vmdk

  4. Command to update the Path Attribute using an "objtool setAttr" (Object Tool Set Attribute): /usr/lib/vmware/osfs/bin/objtool setAttr -u <Object UUID> -d <Path to VMDK>

     Output:  Object set attribute succeeded

  5. Command to check the consistency of the snapshot chain on the VM: vmkfstools -e VM_name.vmdk

     Output: Disk chain is consistent.