O04三、計算節點宕機了怎麼辦

參考 http://www.javashuo.com/article/p-pllqwvvg-cz.html

 

Rebuild 能夠恢復損壞的instance 。那若是是宿主機壞了怎麼辦呢？好比硬件故障或者斷電形成整臺計算機節點沒法工做，該節點上運行的instance如何恢復呢？

 

用shelve或者Migrate可不能夠？很不幸，這兩個操做都要求instance 所在的計算節點的 nova-compute服務正常運行。幸運的是，還有 Evacuate

 

Evacuate 可在 nova-compute 沒法工做的狀況下將節點上的instance 遷移到其餘計算節點上，但有個前提：instance的鏡像文件必須放在共享存儲上

 

咱們能夠經過斷電模擬計算節點故障，而後執行Evacuate 操做恢復 instance。目前Evacuate只能經過CLI 執行。

 

stack@DevStack-Controller:~$ nova help evacuate

usage: nova evacuate [--password <password>] [--force] <server> [<host>]

 

Evacuate server from failed host.

 

Positional arguments:

  <server>               Name or ID of server.

  <host>                 Name or ID of the target host. If no host is

                         specified, the scheduler will choose one.

 

Optional arguments:

  --password <password>  Set the provided admin password on the evacuated

                         server. Not applicable if the server is on shared

                         storage.

  --force                Force to not verify the scheduler if a host is

                         provided. (Supported by API versions '2.29' -

                         '2.latest')

 

其實 Evacuate 是經過rebuild 操做實現的，由於Evacuate 是用共享存儲上的instance的鏡像文件從新建立虛機

 

一、先是 nova-scheduler 選擇新的計算節點

二、nova-compute 在計算節點上執行rebuild操做