Virtual Machine Power On Failure with Disk Module Error "Object type requires hosted I/O" on ESXi

Products

• VMware vSphere ESXi

Issue/Introduction

A virtual machine (VM) fails to power on after an ESXi host failure, reboot, or a failed migration/vMotion operation.

You encounter the following error in the vSphere Client: Module 'Disk' power on failed. Cannot open the disk '/vmfs/volumes/####/####/####.vmdk' or one of the snapshot disks it depends on.

In the /vmfs/volumes/datastore/vmfolder/vmware.log, entries similar to the following are observed:

• • File system specific implementation of LookupAndOpen[file] failed
  • Object type requires hosted I/O
  • failed to open (The specified virtual disk needs repair)

Environment

• VMware vSphere ESXi 7.x
• VMware vSphere ESXi 8.x

Cause

An unexpected failure of the ESXi host, an unclean shutdown, or an interrupted I/O operation (such as a failed migration) can cause the virtual disk metadata to enter a "needs repair" state. This prevents the hypervisor from mounting or locking the virtual disk file.

Resolution

To resolve this issue, you must verify the integrity of the VMDK file and perform a repair using the vmkfstools utility.

Caution: Ensure you have a valid backup of the VMDK descriptor and flat files (including all delta/snapshot files) before proceeding.

1. Enable SSH access to the ESXi host and log in as root.
2. Navigate to the directory containing the virtual machine files: 

   cd /vmfs/volumes/datastore_name/vm_folder_name/

3. Run the following command to check if the disk requires repair: 

   vmkfstools -x check VM_NAME.vmdk

   • If the output shows Disk needs repair, proceed to step 4.
   • If the output shows Disk is error free, the issue may be related to file locks or stale tasks.
4. Run the repair command on the affected VMDK: 

   vmkfstools -x repair VM_NAME.vmdk

5. Once the repair completes successfully, power on the virtual machine from the vSphere Client.

Additional Information

• For instructions on collecting logs, see Collecting diagnostic information for VMware ESXi.
• Refer to the vSphere Storage Virtual Disk Options documentation for further details on disk management.
• To speak with a customer representative or a Support Engineer, see Contact Support. Scroll to the bottom of the page and click on your respective region.