The instant clone feature is not available when you connect directly to ESXi. Instant clone depends on functionality available only in vCenter Server.

Delta disks created during the instant clone operation are not visible in the snapshot trees of the virtual machines. They cannot be managed with the VirtualMachineSnapshot managed object. Instead, you must manage the delta disks using the VirtualMachine.Reconfigure() method.

The instant clone operation is partly parallel and partly serialized. You can start several operations concurrently, but part of the process is exclusive and requires serialization of requests.

The instant clone operation responds to errors by backing out changes, such as delta disks, to restore the previous state of the file system and the source virtual machine. However, there is a small window of failure at the end of the operation where the cloned virtual machine is independent and cannot be backed out to recover from an error. This is a low risk situation.