How to Perform Cold-Migration to Specific Host?

Problem

How to perform VM instance migration to a desired host.

Environment

• Platform9 Managed OpenStack - v5.4.0 and Higher

Procedure

We can follow the below procedure to perform a cold migration to a specific host:

1. Stop a running VM using the GUI/openstack command.
2. Once the VM is stopped perform the migration using - nova migrate --host <target-host-uuid> <instance-uuid>
3. Now, check the status of VM migration activity - openstack server show <instance-uuid> -f value -c status -c progress This should show VERIFY_RESIZE.
4. Confirm the resize using - openstack server resize --confirm <instance-uuid>
5. After the resize is confirmed, verify if the VM instance is on desired host. After confirmation please start the VM instance.

Additional Information

Please note it is always recommended to perform the migration from the GUI, this is exception where VM instances are need to migrate to specific Host.