VM Fails to Power On fails with Error: The system cannot find the file specified or Cannot open the disk

Products

• VMware vSphere ESXi
• VMware vCenter Server

Issue/Introduction

• This article provides solutions for situations where a virtual machine (VM) fails to power on due to missing or invalid virtual machine disk (VMDK) descriptor files or snapshot chain issues.
• The virtual machine cannot power ON and reports errors about missing files or disk dependencies. The error typically involves missing VMDK descriptor or data files, or an inconsistent snapshot chain.
• Different type of errors are as follows:
  
  
  1. Cannot open the disk '/vmfs/volumes/volume/vm/vm-00000#.vmdk' or one of the snapshot disks it depends on.
  2. Cannot open disk '/vmfs/volumes/volume/vm/vm-00000#.vmdk': The parent virtual disk has been modified since the child was created (##).
  3. Some of the disks of the virtual machine vm_name failed to load. The information present for them in the virtual machine configuration may be incomplete.
     
     
  4. vmx| DISKLIB-LINK : "vm.vmdk" : failed to open (The system cannot find the file specified).
  5. vmx| DISKLIB-CHAIN : "vm.vmdk" : failed to open (The system cannot find the file specified).
  6. Hard disks showing as 0 MB in Size.
     
     

Cause

These issues can occur due to:

• Missing or corrupted virtual machine disk (VMDK) descriptor files.
• Inconsistent snapshot chains where a child disk depends on a missing or modified parent disk.

Resolution

To resolve this issue, follow any of the options below:

1. Virtual Machine Disk Files verification:
   
   For each disk (including snapshot disks) verify that the following files are present:

   • Base Disk Descriptor File: vm.vmdk

   • Base Disk Data File: vm-flat.vmdk or vm-separse.vmdk

   • Snapshot Disk Descriptor File: vm-######.vmdk for each snapshot.

   • Snapshot disk data file: vmname-######-delta.vmdk or vmname-######-sesparse.vmdk for each snapshot.
     
     Note: If any of these files are missing, the disk may need to be recreated or restored.
     
     

2. Recreate Missing Descriptor File:

   • Base Disk Descriptor File: If the descriptor file for the base disk is missing, it has to be recreated. For more information, refer: Recreating a missing VMware virtual machine disk descriptor file (.vmdk).

   • Snapshot Disk Descriptor File: If the descriptor file for a snapshot disk is missing, it has to be recreated. For more information, refer: Recreating a missing virtual disk (VMDK) descriptor file for delta disks.
     
     

3. Missing Data File:

   • If data files, such as flat.vmdk, delta.vmdk, sesparse.vmdk files are missing, the VM will have to be restored from a backup or rebuilt.
     
     

4. Check for Inconsistent Snapshot Chains: 

   • If errors regarding "The parent virtual disk has been modified since the child was created" is encountered, then it may be needed to consolidate the snapshot chain or restore the VM from a backup.

Additional Information

• If VM has Raw Device Mapping (RDM) Disks:

  • RDM disks: Will not have flat.vmdk or sesparse.vmdk files for the base disk.

  • Physical-mode RDM: Files will be in the form of vm-rdmp.vmdk.

  • Virtual-mode RDM: Files will be in the form of vm-rdm.vmdk.

  • Base Disk Data File: vm-flat.vmdk or vm-separse.vmdk.

  • RDM descriptor file is missing: It has to be recreated. For more information, refer: Recreating pass-through Raw Device Mapping (RDM) files for a virtual machine
    
    

• Other Useful Links:

  • Verifying ESX/ESXi virtual machine file integrity

  • "The parent virtual disk has been modified since the child was created" error

  • ESXi/ESX host reports VMFS heap warnings when hosting virtual machines that collectively use 4 TB or 20 TB of virtual disk storage