doc/rbd: clarify mirror resync snapshot behavior

Add documentation explaining that rbd mirror resync only copies
image state and data up to the last mirror-snapshot for
snapshot-based mirroring. Document the requirement to create
a new mirror-snapshot on current primary so that new changes
(including resize operation) gets reflected on secondary after
resync.

Fixes: https://tracker.ceph.com/issues/78050
Signed-off-by: Miki Patel <miki.patel132@gmail.com>

diff --git a/doc/rbd/rbd-mirroring.rst b/doc/rbd/rbd-mirroring.rst
index 5357ce215548dc3fa21895bf9f66f9f1773c8f20..dbeaa1797638f7b2fb802d59d629dd6c8a74a617 100644 (file)
--- a/doc/rbd/rbd-mirroring.rst
+++ b/doc/rbd/rbd-mirroring.rst
@@ -558,6 +558,10 @@ For example::
    local cluster's ``rbd-mirror`` daemon process is responsible for performing
    the resync asynchronously.
 
+.. note:: For snapshot-based mirroring, resync replicates the image contents
+   only up to the most recent mirror-snapshot. Create a new mirror-snapshot on
+   the primary image to sync the latest updates.
+
 Mirror Status
 =============