2.6. Using the overcloud-minimal image to avoid using a Red Hat subscription entitlement
By default, director writes the QCOW2
overcloud-full image to the root disk during the provisioning process. The
overcloud-full image uses a valid Red Hat subscription. However, you can also use the
overcloud-minimal image, for example, to provision a bare OS where you do not want to run any other OpenStack services and consume your subscription entitlements.
A common use case for this occurs when you want to provision nodes with only Ceph daemons. For this and similar use cases, you can use the
overcloud-minimal image option to avoid reaching the limit of your paid Red Hat subscriptions. For information about how to obtain the
overcloud-minimal image, see Obtaining images for overcloud nodes.
A Red Hat OpenStack Platform (RHOSP) subscription contains Open vSwitch (OVS), but core services, such as OVS, are not available when you use the
overcloud-minimal image. OVS is not required to deploy Ceph Storage nodes. Use
linux_bond instead of
ovs_bond to define bonds. For more information about
linux_bond, see Linux bonding options.
To configure director to use the
overcloud-minimalimage, create an environment file that contains the following image definition:
parameter_defaults: <roleName>Image: overcloud-minimal
<roleName>with the name of the role and append
Imageto the name of the role. The following example shows an
overcloud-minimalimage for Ceph storage nodes:
parameter_defaults: CephStorageImage: overcloud-minimal
roles_data.yamlrole definition file, set the
Pass the environment file to the
openstack overcloud deploycommand.
overcloud-minimal image supports only standard Linux bridges and not OVS because OVS is an OpenStack service that requires a Red Hat OpenStack Platform subscription entitlement.