Hi All
The title may seem a bit odd because surely yoga is the current release, and zed is the current cycle? This is true, so a little explanation is in order.
As the charm-guide [1] explains, in the previous cycle, the OpenStack, and supporting, charms moved from a single stable charm (for each component) that supported multiple releases, to a charm+track that targets a specific release [2]. The current release for the OpenStack charms is 'yoga' and thus there is a yoga/stable track. For a full explanation, please see [1].
Today, as part of our ongoing charmhub stable migration work this cycle, we have (re)released the 21.10 charms (that supported queens -> xena) as "xena" charms for OpenStack, "pacific" charms for Ceph, and "21.09" charms for OVN. The xena, pacific and 21.09-OVN channel charms have the same features as the existing 21.10 charms, include bug-fixes and relevant backports since the 21.10 charms were released, and have been re-tested and verified as a set prior to being released to the xena/stable channel. The full list of charms for a "Xena" OpenStack system, including ceph, OVN, mysql8, hacluster, rabbitmq-server, vault and others can be seen in the docs at [3].
The xena/pacific/21.09 charms have been designed to be upgradable from the 21.10 charms if you are running a xena OpenStack, but please consult the docs [4] about how to go about upgrading charms. The charms also are able to perform the OpenStack upgrade from wallaby -> xena, and again please consult the docs [5] for upgrading OpenStack.
Our next stable maintenance release will be wallaby/pacific/20.12 (ovn), so please keep an eye out on the mailing lists.
Thanks!