Realms
A realm represents a globally unique namespace consisting of one or more zonegroups containing one or more zones, and zones containing buckets, which in turn contain objects. A realm enables the Ceph Object Gateway to support multiple namespaces and their configuration on the same hardware.
A realm contains the notion of periods. Each period represents the state of the zone group and
zone configuration in time. Each time you make a change to a zonegroup or zone, update the period
and commit it.
Important: Create realms for new clusters.