tripleo-docs/doc/source/post_deployment/scale_roles.rst

Scaling overcloud roles

If you want to increase or decrease resource capacity of a running overcloud, you can start more servers of a selected role or delete some servers if capacity should be decreased. First update the Overcloud plan with a new number of nodes of the role:

openstack management plan set $PLAN_UUID -S Compute-1=5

Note

The role is specified including the role version. Both role names and role versions can be listed with command:

openstack role list

And then re-deploy the Overcloud with the updated plan:

openstack overcloud deploy --plan $PLAN_UUID

Note

Scaling out assumes that newly added nodes has already been registered in Ironic.

Note

When scaling down random servers of specified role will be deleted, how to delete specific nodes is decribed in delete_nodes.

Scaling overcloud roles without using Tuskar

If the overcloud was deployed from heat templates directly <../advanced_deployment/template_deploy> then you can just re-deploy the overcloud with --templates and --<role>-scale parameters:

openstack overcloud deploy --templates [templates dir] --compute-scale 5

If you passed any extra environment files when you created the overcloud (for instance, in order to configure network isolation <../advanced_deployment/network_isolation>), you must pass them again here using the -e or --environment-file option to avoid making undesired changes to the overcloud.