def create_image(self, prepare_template, base, size, *args, **kwargs):    

        import pydevd    

        pydevd.settrace('192.168.10.10', port=51234, stdoutToServer=True, stderrToServer=True)    

        if self.rbd is None:    

            raise RuntimeError(_('rbd python libraries not found'))    

        if not os.path.exists(base):      #检查路径是否存在    

            prepare_template(target=base, max_size=size, *args, **kwargs)    

        else:    

            self.verify_base_size(base, size)      #验证size是否满足要求，同之前博客本地file创建分析一致    

        # keep using the command line import instead of librbd since it    

        # detects zeroes to preserve sparseness in the image    

        args = ['--pool', self.pool, base, self.rbd_name]      #构造虚拟机文件生成参数    

        if self._supports_layering():    

            args += ['--new-format']    

        args += self._ceph_args()    

        libvirt_utils.import_rbd_image(*args)      #根据到1.1    

        base_size = disk.get_disk_size(base)      #求出base镜像模板文件大小    

        if size and size > base_size:      #见图1-1：    

            self._resize(self.rbd_name, size)      #跟进到1.2    

('rbd' 'import' '--pool', 'nova', '/var/lib/nova/instances/_base/8b925177989924ee3e316b28b3abc03a829fbb29', 'fec8e16e-0055-4117-aa5c-afbd845773f2_disk', '--new-format', '--id', 'admin', '--conf', '/etc/ceph/ceph.conf')    

          def _resize(self, volume_name, size):    

        size = int(size) * units.Ki       #见图1.2-1    

        with RBDVolumeProxy(self, volume_name) as vol:    

            vol.resize(size)      #根据见1.3