diff --git a/docs/en-US/Release_Notes.xml b/docs/en-US/Release_Notes.xml
index 2f32a565970..ae83455812c 100644
--- a/docs/en-US/Release_Notes.xml
+++ b/docs/en-US/Release_Notes.xml
@@ -221,6 +221,28 @@ under the License.
check policies in the cloud. You can override this value for an individual health check
policy.
+
+ Snaphotting, backups, cloning and System VMs for RBD Primary Storage
+
+ These new RBD features require at least librbd 0.61.7 (Cuttlefish) and libvirt 0.9.14
+ on the KVM hypervisors.
+
+ With this release &PRODUCT; will leverage the features of RBD format 2. This allows
+ snapshotting and backing up those snapshots.
+ Backups of snapshots to Secondary Storage are full copies of the RBD snapshot,
+ they are not RBD diffs. This because when restoring a backup of a snapshot it is not mandatory
+ that this backup is deployed on RBD again, it could also be a NFS Primary Storage.
+ Another key feature of RBD format 2 is cloning and with this release templates will
+ be copied to Primary Storage once and using the cloning mechanism new disks will be cloned
+ from this parent template. This saves space and decreases deployment time for Instances
+ dramatically.
+ Before this release a NFS Primary Storage was still required for running the System VMs
+ from. The reason behind this was a so called 'patch disk' which was generated by the hypervisor
+ which contained metadata for the System VM. The scripts generating this disk didn't support
+ RBD and thus System VMs had to be deployed from NFS. With 4.2 instead of the patch disk a
+ VirtIO serial console is used to pass meta information to System VMs. This enabled the deployment
+ of System VMs on RBD Primary Storage.
+