題記：

在我們學習openstack知識過程中，經常會部署幾臺物理伺服器，但是也有可能某些物理伺服器另作他用，也就是物理伺服器修改IP或者角色轉換，但是可能這些物理伺服器作為宿主機（計算節點）還包含了已經執行的虛擬機器例項，類似這種情況，我們無法直接將計算節點暴力清除（也就是斷開網路），這樣操作會出現一個問題就是，實際的計算節點資訊在資料庫中並沒有清除，導致我們在建立新的虛擬機器伺服器預設還會進行排程，但是實際這些計算節點是不存在的，所以我們需要有步驟的對這些進行操作。

1，刪除例項

[email protected]:~$ nova list
+--------------------------------------+--------------------------------------------+---------+------------+-------------+---------------------------+
| ID                                   | Name                                       | Status  | Task State | Power State | Networks                  |
+--------------------------------------+--------------------------------------------+---------+------------+-------------+---------------------------+
| 0d9d319b-3387-4ee1-93db-d98f03c20621 | devstack_icehouse                          | SHUTOFF | -          | Shutdown    | sharednet1=192.168.12.105 |
| decf3b3b-2bc7-4bb3-af0e-ef12479778b6 | hadoop                                     | ACTIVE  | -          | Running     | sharednet1=192.168.12.125 |
| e0482e04-7c85-45cf-97a0-7ef0f0203871 | idesktop                                   | SHUTOFF | -          | Shutdown    | sharednet1=192.168.12.112 |
| 088844ae-c012-4d35-83d0-dc3a06a1ef8a | mq_ha-088844ae-c012-4d35-83d0-dc3a06a1ef8a | ACTIVE  | -          | Running     | sharednet1=192.168.12.129 |
| 0b095133-8c76-4a8c-acfd-a66948920089 | mq_ha-0b095133-8c76-4a8c-acfd-a66948920089 | ACTIVE  | -          | Running     | sharednet1=192.168.12.131 |
| 4b1c2010-3a9e-42b8-971d-86118c108f2d | mq_ha-4b1c2010-3a9e-42b8-971d-86118c108f2d | ACTIVE  | -          | Running     | sharednet1=192.168.12.130 |
| 582dddf4-5d33-4689-a946-d5958aa263d6 | ubuntu1404_server_LIWH                     | ACTIVE  | -          | Running     | sharednet1=192.168.12.143 |
| 6c16999c-e94a-4947-8489-1333d28862f8 | vm2                                        | ACTIVE  | -          | Running     | sharednet1=192.168.12.116 |
+--------------------------------------+--------------------------------------------+---------+------------+-------------+---------------------------+
 
[email protected]:~$ nova delete devstack_icehouse

2，移除nova-compute

查詢所有nova 服務

[email protected]:~$ nova service-list
+------------------+------------+----------+----------+-------+----------------------------+------------------------------------+
| Binary           | Host       | Zone     | Status   | State | Updated_at                 | Disabled Reason                    |
+------------------+------------+----------+----------+-------+----------------------------+------------------------------------+
| nova-cert        | controller | internal | enabled  | up    | 2016-01-08T03:01:20.000000 | -                                  |
| nova-consoleauth | controller | internal | enabled  | up    | 2016-01-08T03:01:27.000000 | -                                  |
| nova-scheduler   | controller | internal | enabled  | up    | 2016-01-08T03:01:28.000000 | -                                  |
| nova-conductor   | controller | internal | enabled  | up    | 2016-01-08T03:01:24.000000 | -                                  |
| nova-compute     | compute    | nova     | enabled  | up    | 2016-01-08T03:01:20.000000 | None                               |
| nova-compute     | network    | nova     | enabled  | up    | 2016-01-08T03:01:29.000000 | None                               |
| nova-compute     | compute2   | nova     | disabled | down  | 2016-01-07T07:37:07.000000 | AUTO: Failed to connect to libvirt |
+------------------+------------+----------+----------+-------+----------------------------+------------------------------------+
 

在J 版本以上有nova service-delete compute2 直接刪除 

Juno之前版本可以用nova service-disable 

執行  nova service-disable compute2 nova-compute

[email protected]:~# nova service-disable compute2 nova-compute
+----------+--------------+----------+
| Host     | Binary       | Status   |
+----------+--------------+----------+
| compute2 | nova-compute | disabled |
+----------+--------------+----------+
 
[email protected]:~# nova service-list
+------------------+------------+----------+----------+-------+----------------------------+-----------------+
| Binary           | Host       | Zone     | Status   | State | Updated_at                 | Disabled Reason |
+------------------+------------+----------+----------+-------+----------------------------+-----------------+
| nova-cert        | controller | internal | enabled  | up    | 2016-01-13T03:17:46.000000 | -               |
| nova-consoleauth | controller | internal | enabled  | up    | 2016-01-13T03:17:39.000000 | -               |
| nova-scheduler   | controller | internal | enabled  | up    | 2016-01-13T03:17:42.000000 | -               |
| nova-conductor   | controller | internal | enabled  | up    | 2016-01-13T03:17:42.000000 | -               |
| nova-compute     | compute    | nova     | enabled  | up    | 2016-01-13T03:17:47.000000 | None            |
| nova-compute     | network    | nova     | enabled  | up    | 2016-01-13T03:17:39.000000 | None            |
| nova-compute     | compute2   | nova     | disabled | up    | 2016-01-13T03:17:41.000000 | -               |
+------------------+------------+----------+----------+-------+----------------------------+-----------------+

3，登入nova資料庫清理 如下資料

mysql -unovadbadmin -pnovapasswd

select * from nova.services;
select * from compute_nodes
delete from nova.services where host="compute2";
delete from compute_nodes where hypervisor_hostname="compute";

 4，關機移除compute2