openstack从镜像创建volume失败

Question

1.horzion上创建volume时失败（相同的条件，之前创建成功过，后来被我删了）

2.附上部分volume.log
[root@host-193-160-32-87 cinder]# tail -f volume.log
2017-10-16 15:07:45.282 16642 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/taskflow/engines/action_engine/executor.py", line 53, in _execute_task
2017-10-16 15:07:45.282 16642 ERROR oslo_messaging.rpc.server result = task.execute(**arguments)
2017-10-16 15:07:45.282 16642 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/cinder/volume/flows/manager/create_volume.py", line 902, in execute
2017-10-16 15:07:45.282 16642 ERROR oslo_messaging.rpc.server **volume_spec)
2017-10-16 15:07:45.282 16642 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/cinder/volume/flows/manager/create_volume.py", line 807, in _create_from_image
2017-10-16 15:07:45.282 16642 ERROR oslo_messaging.rpc.server image_meta['size'], image_id)
2017-10-16 15:07:45.282 16642 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/cinder/image/image_utils.py", line 493, in check_available_space
2017-10-16 15:07:45.282 16642 ERROR oslo_messaging.rpc.server raise exception.ImageUnacceptable(image_id=image_id, reason=msg)
2017-10-16 15:07:45.282 16642 ERROR oslo_messaging.rpc.server ImageUnacceptable: u6620u50cf 30e2173c-6e20-47d1-9687-3a50f60a4fff u65e0u6cd5u63a5u53d7uff0cu539fu56e0u662fuff1a There is no space to convert image. Requested: 2654867968, available: 421351424
2017-10-16 15:07:45.282 16642 ERROR oslo_messaging.rpc.server
3.有没有大牛告知一下： available: 421351424，这串数字是指什么？