Chapter 4. Technology previews

This section provides an overview of Technology Preview features introduced or updated in this release of Red Hat Ceph Storage.


Technology Preview features are not supported with Red Hat production service level agreements (SLAs), might not be functionally complete, and Red Hat does not recommend to use them for production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information on Red Hat Technology Preview features support scope, see

4.1. Ceph File System

CephFS snapshots

Ceph File System (CephFS) supports taking snapshots as a Technology Preview. Snapshots create an immutable view of the file system at the point in time they are taken.

4.2. Block Devices (RBD)

Mapping RBD images to NBD images

The rbd-nbd utility maps RADOS Block Device (RBD) images to Network Block Devices (NBD) and enables Ceph clients to access volumes and images in Kubernetes environments. To use rbd-nbd, install the rbd-nbd package. For details, see the rbd-nbd(7) manual page.

4.3. Object Gateway

Object Gateway archive site

With this release an archive site is supported as a Technology Preview. The archive site allows you to have a history of versions of S3 objects that can only be eliminated through the gateways associated with the archive zone. Including an archive zone in a multizone configuration allows you to have the flexibility of an S3 object history in only one zone while saving the space that the replicas of the versions S3 objects would consume in the rest of the zones.

Tiering within a cluster by disk type

This release adds the ability to tier within a cluster by disk type as a Technology Preview by using the capabilities for mapping for example pools to placement targets and storage classes. Using lifecycle transition rules, it is possible to cause objects to migrate between storage pools based on policy.

S3 bucket notifications

S3 bucket notifications are now supported as a Technology Preview. When certain events are triggered on an S3 bucket, the notifications can be sent from the Ceph Object Gateway to HTTP, Advanced Message Queuing Protocol (AMQP) 9.1, and Kafka endpoints. Additionally, the notifications can be stored in a “PubSub” zone instead of, or in addition to sending them to the endpoints. “PubSub” is a publish-subscribe model that enables recipients to pull notifications from Ceph.

To use the S3 notifications, install the librabbitmq and librdkafka packages.