Multisite sync is based on logs of data and metadata changes, which will continue to grow over time. Log entries should be trimmed periodically once it can be proved that no other zone will need to read them. https://trello.com/c/4IWMXSWa/14-data-metadata-log-and-bucket-index-trimming-for-multisitev2
Data log Trimming has landed, it is now tracked at https://bugzilla.redhat.com/show_bug.cgi?id=1438895 This RFE remains open to track metadata log and bucket index trimming.
This feature is verified for ceph version 12.2.1-37.el7cp.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2017:3387