Clone vm without vCSA

SW INFO:

-ESXi 6.7

I am trying to clone a vm without vCenter

My plans are:

-clone vmdk

-create an empty vm

-attach cloned disk into new vm

I got this error when trying to clone

# vmkfstools -i WIN2016/WIN2016.vmdk AD1/AD1.vmdk

DiskLib_Check() failed for source disk The system cannot find the file specified (25).

Google said need to install multiextent module, but I can't find it.

# vmkload_mod -l|grep multiextent

QUESTIONS:

1. Do I need multiextent in esxi 6.7

2. I also try to
# cp old*.vmdk new*.vmdk
but I can see the disk when I am trying to attach using GUI

tq