执行
$ nova resize instance1
时候出错：
{"message": "Proxy error: 502 Read from server failed: Timeout.: 502 Read from server failed: Timeout: The following error occurred while trying to access http://172.16.13.140:9292/v1/images/bca45fe3-9f30-423e-ac74-80d98ef0a50e:: Generated Fri, 06 Jan 2017 11:00:44 HK", "code": 500, "details": " File \"/opt/stack/nova/nova/compute/manager.py\", line 375, in decorated_function
解决方法：
到instance1所在的server上，执行
$screen -x stack
然后进入n－cpu服务：
$ unset http_proxy
$ unset https_proxy
$ unset no_proxy
就OK了