[root@controller nova]# su -s /bin/sh -c “nova-manage db sync” nova
/usr/lib/python2.7/site-packages/pymysql/cursors.py:170: Warning: (1831, u’Duplicate index block_device_mapping_instance_uuid_virtual_name_device_name_idx. This is deprecated and will be disallowed in a future release.‘)
result = self._query(query)
/usr/lib/python2.7/site-packages/pymysql/cursors.py:170: Warning: (1831, u’Duplicate index uniq_instances0uuid. This is deprecated and will be disallowed in a future release.’)
result = self._query(query)
根據提示：uuid重復了，這里算是警告信息把？不用管它也行，沒有提示error
原因：這個警告表明在nova數據庫中存在重復的索引。在未來的MariaDB版本中，這將是不允許的。為了解決這個問題，你需要刪除重復的索引。以下是詳細的步驟：
登錄數據庫：
選擇 nova數據庫
查詢和刪除：
MariaDB [nova]> SHOW INDEX FROM instances;
MariaDB [nova]> ALTER TABLE instances DROP INDEX uniq_instances0uuid;
刪除后：
再次執行：
[root@controller nova]# su -s /bin/sh -c "nova-manage db sync" nova
MariaDB [(none)]> use nova;
MariaDB [nova]> SHOW INDEX FROM instances;
