http://ceph.com/releases/v12-2-0-luminous-released/
This is the first release of Luminous v12.2.x long term stable release
series. There have been major changes since Kraken (v11.2.z) and
Jewel (v10.2.z), and the upgrade process is non-trivial. Please read
these release notes carefully. The next stable release will be named
Mimic.