Exporting a Running Virtual Machine or vApp from vSphere
You must power off a virtual machine or vApp before exporting it. The following example locates the virtual machine or vApp based on its DNS name through the vCenter Server and powers it off:
> ovftool --powerOffSource
vi://MyvCenterServer/?dns=test-vm test-vm.ova
Note:
This option does not perform a shutdown of the operating system. This is only a power off operation.