Without linked clone two VM using the same image can't run
        at the same time.

        To avoid issue like false detection when a project close
        and another open we try multiple times.

def _check_duplicate_linked_clone(self):
        """
        Without linked clone two VM using the same image can't run
        at the same time.

        To avoid issue like false detection when a project close
        and another open we try multiple times.
        """
        trial = 0

        while True:
            found = False
            for node in self.manager.nodes:
                if node != self and node.vmx_path == self._vmx_path:
                    found = True
                    if node.project != self.project:
                        if trial >= 30:
                            raise VMwareError("Sorry a node without the linked clone setting enabled can only be used once on your server.\n{} is already used by {} in project {}".format(self.vmx_path, node.name, self.project.name))
                    else:
                        if trial >= 5:
                            raise VMwareError("Sorry a node without the linked clone setting enabled can only be used once on your server.\n{} is already used by {} in this project".format(self.vmx_path, node.name))
            if not found:
                return
            trial += 1
            yield from asyncio.sleep(1)