Rebuilding Instances

Owned by Chung, Donald (STFC,RAL,SC)
Last updated: Aug 16, 2023 by Chris Green
7 min read

Warning!!! Rebuilding Instances will result in loss of data.

OpenStack has a useful rebuild function that allows you to rebuild an instance from a fresh image while maintaining the same fixed and floating IP addresses, amongst other metadata.

Web Interface

  1. In Web Interface Compute->Instances, select the VM you wish to associate the floating IP

  2. Click the drop-down menu on the right-hand side (in Actions column) and select REBUILD INSTANCE

  3. Select the image from the drop-down menu in the pop-up. Click on the REBUILD button.

  4. The instance will be rebuilt with the new image



Command-Line

Get the Server ID (Instance) and the Image ID

$ openstack image list +--------------------------------------+----------------------------------------------------------+-------------+ | ID | Name | Status | +--------------------------------------+----------------------------------------------------------+-------------+ | ae4a8e18-627c-484a-9909-7bd93d9e3e97 | ubuntu-focal-20.04-gui | active | +--------------------------------------+----------------------------------------------------------+-------------+ $ openstack server list +--------------------------------------+--------------------------+--------+----------------------------------------+---------------------------------------------------------+--------------+ | ID | Name | Status | Networks | Image | Flavor | +--------------------------------------+--------------------------+--------+----------------------------------------+---------------------------------------------------------+--------------+ | b5acb398-76b4-48fe-9b9a-d480636fdfd9 | test-rebuild | ACTIVE | Internal=172.16.101.195 | scientificlinux-7-nogui | c3.small | +--------------------------------------+--------------------------+--------+----------------------------------------+---------------------------------------------------------+--------------+



Run

openstack server rebuild --image <image-id> <server-id>



$ openstack server rebuild --image ae4a8e18-627c-484a-9909-7bd93d9e3e97 b5acb398-76b4-48fe-9b9a-d480636fdfd9 +-------------------+------------------------------------------------------------------+ | Field | Value | +-------------------+------------------------------------------------------------------+ | OS-DCF:diskConfig | MANUAL | | accessIPv4 | | | accessIPv6 | | | addresses | Internal=172.16.101.195 | | adminPass | yoTq5HDrhH6a | | created | 2021-12-03T10:31:27Z | | flavor | c3.small (026ace2c-5247-4bdc-8929-81d129cc69bf) | | hostId | ff3c5830640867370bd8fb9228356baee63ff24e5baa381e41798dc9 | | id | b5acb398-76b4-48fe-9b9a-d480636fdfd9 | | image | ubuntu-focal-20.04-gui (ae4a8e18-627c-484a-9909-7bd93d9e3e97) | | name | test-rebuild | | progress | 0 | | project_id | 80ab2bd11e5f46bf96bf47658d07499d | | properties | | | status | REBUILD | | updated | 2021-12-03T10:57:41Z | | user_id | 3ae4ecf4b9e0e66260b7aaebc2cc98aac3c95221e42f1cb49113ed751d8b9f2c | +-------------------+------------------------------------------------------------------+