Agentless Protection - Unable to access file since it is locked (4038969)

To prevent concurrent changes to critical virtual machine files, locks are placed on these files.

In certain circumstances, these locks may not be released. VMware snapshot deletion and consolidation processes will fail if the locks are not released.

You will see the following error in the vSphere environment:

Unable to access a file <filename> since it is locked

A couple of the identified causes are:

• The process to unmount Hot-Added disks has failed. So the VM's, that were backed up, have disks still mounted to the Rapid Recovery Core VM
• The ESXi host has not removed the lock because  a communication error occured between the Rapid Recovery Core and the ESXi host.

For cases where the hot-added disk has not been unmounted:

• Within your vSphere environment, edit the VM settings of your Virtual Machine,
• Identify and remove the disks that do not belong to the Virtual Machine. 
  NOTE: Do NOT select the option to delete files from disk
• Create a new VMware snapshot on the VM(s) that were still mounted to the Virtual Machine
• Use the Delete All option to delete all snapshots from the Snapshot Manager

For cases where the ESXi host has failed to remove the lock, the management service on the host will need to be restarted.

• Follow the procedures in https://kb.vmware.com/kb/1003490
  • From the ESXi Direct Console User Interface (DCUI):
    Connect to the console of your ESXi host.
    Press F2 to customize the system.
    Log in as root.
    Use the Up/Down arrows to navigate to Restart Management Agents.
    Note: In ESXi 4.1 and ESXi 5.0, 5.1, 5.5 and 6.0 this option is available under Troubleshooting Options.
    Press Enter.
    Press F11 to restart the services.
    When the service restarts, press Enter.
    Press Esc to log out of the system.
  • From the ESXi Local Console or SSH:

    Log in to SSH or Local console as root.

    Run these commands:

    /etc/init.d/hostd restart

    /etc/init.d/vpxa restart
• Create a new VMware snapshot on the VM(s) that were still mounted to the Rapid Recovery Core.
• Use the Delete All option to delete all snapshots from the Snapshot Manager