def METHOD_NAME(self):
    """create one snapshot, create one new file"""
    self.generate_tempfile(self.disks_info[self.base_tag][1],
                           filename="base",
                           size=self.params["tempfile_size"])
    self.snapshot_chain = [self.base_tag] + self._snapshot_images
    for idx in range(1, len(self.snapshot_chain)):
        backup_utils.blockdev_snapshot(
            self.main_vm,
            "drive_%s" % self.snapshot_chain[idx-1],
            "drive_%s" % self.snapshot_chain[idx]
        )
        self.generate_tempfile(self.disks_info[self.base_tag][1],
                               filename=self.snapshot_chain[idx],
                               size=self.params["tempfile_size"])