Openstack Migrate Instance Workaround

This post is aimed at giving you about How to Migrate an OpenStack Instance across compute nodes.

Case A. boot volume on ephemeral disk

STOPPED/SHUTDOWN/PAUSED instances: migration

Migration for ephemeral instances with status stopped/suspended/paused:

$ openstack server migrate <intance_uuid>

Alternatively you can use the Nova command for the migration:

$ nova migrate --poll <intance_uuid>

After the migration command it will be necessary confirm the resize:

$ openstack server resize confirm <instance_uuid>

or

$ nova resize-confirm <instance_uuid>

ACTIVE instances: live migration

If the instance is built on Ephemeral storage, live migration is possible with the following command:

$ openstack server migrate <instance_uuid> --live <compute_target_host> --block-migration

Alternatively you can use the Nova command for the migration:

$ nova live-migration --block-migrate <instance_uuid> <compute_target_host>

After the migration, make sure to check if the istance needs a resize confirmation.

Case B: boot volume on non-ephemeral (Ceph) disk

STOPPED/SHUTDOWN/PAUSED instances: migration

Migration for non-ephemeral instances with status stopped/suspended/paused:

$ openstack server migrate --wait <instance_uuid>

ACTIVE instances: live migration

If the instance is built on Ceph volume, execute:

$ openstack server migrate <instance_uuid> --live <compute_target_host>

If the previous command returns an error, you can try with --block-migration option:

$ openstack server migrate <instance_uuid> --live <compute_target_host> --block-migration

Alternatively you can use the Nova command for the migration:

$ nova live-migration <instance_uuid>

Obstacle Workaround

If the openstack server shows  status is still migrating, execute the reset state command below [ignore if the instance status is already ACTIVE]

$ nova migration-list --instance-uuid <instance-uuid>
$ nova live-migration-abort <instance-uuid> <migration-id>
$ nova reset-state --active <instance-uuid>