Home > Storage > PowerMax and VMAX > Storage Admin > Dell PowerMax: Ansible Modules Best Practices > Creating cascaded storage groups
Cascaded storage groups are often used in large configurations or in configurations where control is needed over subsets of volumes in the same masking view. For example, you might use a cascaded storage group when providing different levels of service to volumes or creating snapshots of a subset or superset of volumes.
To create a cascaded storage group, create an empty storage group that will be the parent and then creating any child storage groups. Finally, create a task to ensure that all the child storage groups are added to the child.
As shown in Figure 11, a level of service can only be provided for a device in one storage group. The first task creates the storage group for the parent, with srp set to “None” and service_level set to “None”, which ensures that the playbook will run without error. The example can be found on GitHub here.