During a backup process
During a backup process, the NetBackup for OpenStack cluster is also responsible to gathering the metadata about the backed-up virtual machines and networks from the OpenStack environment. It sends API calls towards the OpenStack endpoints on the configured endpoint type to fetch this information. Once the metadata has been received the NetBackup for OpenStack Cluster writes it as JSON files on the Backup Target.
The NetBackup for OpenStack cluster also sends the Cinder Snapshot command.