From c6651ff309a8a8c0deb5225bdbdc10038146347d Mon Sep 17 00:00:00 2001 From: Jason Dillaman Date: Thu, 4 Oct 2018 12:21:35 -0400 Subject: [PATCH] doc/rbd: explicitly state that mirroring requires connectivity to cluster Signed-off-by: Jason Dillaman --- doc/rbd/rbd-mirroring.rst | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/doc/rbd/rbd-mirroring.rst b/doc/rbd/rbd-mirroring.rst index 512b323997db8..2ccddde93e47c 100644 --- a/doc/rbd/rbd-mirroring.rst +++ b/doc/rbd/rbd-mirroring.rst @@ -15,8 +15,21 @@ the image within the local cluster. .. note:: RBD mirroring requires the Ceph Jewel release or later. -.. important:: To use RBD mirroring, you must have two Ceph clusters, each - running the ``rbd-mirror`` daemon. +Depending on the desired needs for replication, RBD mirroring can be configured +for either one- or two-way replication: + +* **One-way Replication**: When data is only mirrored from a primary cluster to + a secondary cluster, the ``rbd-mirror`` daemon runs only on the secondary + cluster. + +* **Two-way Replication**: When data is mirrored from primary images on one + cluster to non-primary images on another cluster (and vice-versa), the + ``rbd-mirror`` daemon runs on both clusters. + +.. important:: Each instance of the ``rbd-mirror`` daemon must be able to + connect to both the local and remote Ceph clusters simultaneously (i.e. + all monitor and OSD hosts). Additionally, the network must have sufficient + bandwidth between the two data centers to handle mirroring workload. Pool Configuration ================== -- 2.39.5