Rollback a compute node¶

You can rollback a compute node to its original state, for example, the state before it failed.

To rollback a compute node:

1. SSH to one of the controller nodes.

2. Put the node into maintenance mode to prevent scheduling of new VMs by disabling the nova-compute service:

   $ nova service-disable <host> nova-compute
   

3. Power off all the VMs running on the node to be re-installed:

   $ nova stop [vm-uuid]
   

   Alternatively, live migrate the VMs:

   1. Get a list of all VMs running on a host:

      $ nova list --host <host> --all-tenants
      

   2. Manually live migrate instances to other hosts:

      $ nova live-migration <instance>
      

4. Reinstall the node as described in Reinstall a node.

5. Enable the nova-compute service:

   $ nova service-enable <host> nova-compute
   

6. If you did not perform the live migration, start the VMs that are in the SHUTOFF status:

   $ nova start [vm-uuid]