From: Hans Bogert Date: Thu, 28 May 2020 22:06:30 +0000 (+0200) Subject: doc: rbd-mirroring: Explain snapshot mirroring X-Git-Tag: v16.1.0~2203^2 X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=refs%2Fpull%2F35303%2Fhead;p=ceph.git doc: rbd-mirroring: Explain snapshot mirroring * Rectify that snapshot based mirroring is point-in-time consistent * Reword slightly s.t. there is less repetition. Based on the discussion in https://lists.ceph.io/hyperkitty/list/ceph-users@ceph.io/thread/G6ZW5OP4IXGUBAJTKZDPABK7HCKYISQH/ Signed-off-by: Hans van den Bogert --- diff --git a/doc/rbd/rbd-mirroring.rst b/doc/rbd/rbd-mirroring.rst index 9e83aa58baee..8315a89132f2 100644 --- a/doc/rbd/rbd-mirroring.rst +++ b/doc/rbd/rbd-mirroring.rst @@ -21,10 +21,10 @@ capability is available in two modes: updates between two mirror-snapshots and copy the deltas to its local copy of the image. With the help of the RBD fast-diff image feature, updated data blocks can be quickly computed without the need to scan the full RBD image. - Since this mode is not point-in-time consistent, the full snapshot delta will - need to be synced prior to use during a failover scenario. Any partially - applied snapshot deltas will be rolled back to the last fully synced snapshot - prior to use. + Since this mode is not as fine-grained as journaling, the complete delta + between two snapshots will need to be synced prior to use during a failover + scenario. Any partially applied set of deltas will be rolled back at moment + of failover. .. note:: journal-based mirroring requires the Ceph Jewel release or later; snapshot-based mirroring requires the Ceph Octopus release or later.