错误： 实例 "ahwater-linux-core" 执行所请求操作失败，实例处于错误状态。: 请稍后再试 [错误: Exceeded maximum number of retries. Exceeded max scheduling attempts 3 for instance 7c1609c9-9d0f-4836-85b3-cefd45f942a7. Last exception: [u'Traceback (most recent call last):\n', u' File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 1].