Troubleshooting Instant Clones in the Internal VM Debug Mode

You can use the internal VM debug mode to troubleshoot internal virtual machines in instant clone farms. With the internal VM debug mode, you can analyze failed internal virtual machines before these virtual machines are deleted. You must enable the internal VM debug mode before you create an instant clone farm.

Procedure

1. In the vSphere Web Client, select the golden VM, and click Manage > Configure > VM Options > Edit > VM Options > Advanced > Edit Configuration.
   The Configuration Parameters window displays a list of parameter names and values.
2. In the Configuration Parameters window, search for the cloneprep.debug.mode parameter.
   If the golden VM does not have the cloneprep.debug.mode parameter, you must add cloneprep.debug.mode as the parameter name and add a value of ON or OFF. If the golden VM has the cloneprep.debug.mode parameter, you can change the value of the parameter to ON or OFF.
3. Enable or disable the internal VM debug mode for internal VMs.
   • To enable the internal VM debug mode, set the value of cloneprep.debug.mode to ON. If you enable the internal VM debug mode, the internal VMs are not locked and cannot be deleted by Connection Server.
   • To disable the internal VM debug mode, set the value of cloneprep.debug.mode to OFF. If you disable the internal VM debug mode, the internal VMs are locked and can be deleted by Connection Server.
   For instant clone actions such as prime, provision, resync, or unprime, the internal virtual machines use the value set in the golden virtual machine. If you do not disable the internal VM debug mode, then the VMs remain in vSphere till you delete the VMs. For further debugging on instant clone actions, you can also log in to the internal VM and view the instant clone logs. You can also see the following VMware Knowledge Base articles for further debugging on instant clone actions:

   • Differences between VMware ClonePrep, QuickPrep and Microsoft Sysprep (2003797) https://kb.vmware.com/s/article/2003797
   • Initial publish of an Instant Clone desktop pool image fails and the template VMs are deleted (2144938) https://kb.vmware.com/s/article/2144938
   • Computer-based Global Policy Objects (GPOs) that require reboot are not applied on Instant Clones (2150495) https://kb.vmware.com/s/article/2150495
   • How to change SVGA settings for Instant Clone Pools (2151745) https://kb.vmware.com/s/article/2151745

   See also "Upgrade Instant-Clone Desktop Pools When You Upgrade vCenter Server to vSphere 6.7 or Later" in the Horizon Upgrades document.