PrlVm_CloneEx command flags set 

PCVF_DETACH_EXTERNAL_VIRTUAL_HDD

• to remove link to Virtual Hdd which located outside of VM.pvm directory from cloned vm configuration.

enum _PRL_CLONE_VM_FLAGS {
  PCVF_CLONE_TO_TEMPLATE = 1<<(PACF_MAX+1),
  PCVF_CHANGE_SID = 1<<(PACF_MAX+2),
  PCVF_LINKED_CLONE = 1<<(PACF_MAX+3),
  PCVF_IMPORT_BOOT_CAMP = 1<<(PACF_MAX+4),
  PCVF_DETACH_EXTERNAL_VIRTUAL_HDD = 1<<(PACF_MAX+5)
};