Please add a note in the RHCS 4 to RHCS 5 upgrade section to mention that if the customer is upgrading a multisite environment, the sync will not work until both the sites are upgraded to RHCS 5.3. As this is not mentioned in the doc, many customers are upgrading one site and then coming back complaining about the multisite sync is broken. Reported by: rhn-support-trchakra https://access.redhat.com/documentation/en-us/red_hat_ceph_storage/5/html/upgrade_guide/upgrading-a-red-hat-ceph-storage-cluster-running-rhel-8-from-rhcs-4-to-rhcs-5#annotations:16d17d60-589b-41d3-95ef-5cec3bd6c11f