What should be perfect configuration to convert VM into Template from CLI ?

Hello Team,

I tried to convert template from a VM using vim-cmd vmsvc/convert.toTemplate 1

And I am facing this error:

(vmodl.fault.NotSupported) {

   faultCause = (vmodl.MethodFault) null,

   msg = "Received SOAP response fault from [<cs p:1f2aea80, TCP:localhost:80>]: markAsTemplate

The operation is not supported on the object."

}

So, Is it supported in ESXi 6.0 ? If yes then what should be proper configuration?

Thanks

Kshitij