How to completely delete /var/lib/mysql and bootstrap galera in Red Hat OpenStack Platform

Issue

WARNING: The operations in this guide are not meant to be executed by users on production systems and are here for informational purposes only. If these operations are wrongly executed, they may lead to total loss of the overcloud's data and subsequently to a complete outage of the overcloud which may not be possible to revert. Please be aware of this and that you may lose support if you execute any of the actions below without confirmation from Red Hat support. Please contact Red Hat support before considering to apply the actions in this guide on any OpenStack cluster.

WARNING: The following procedure will lead to a complete outage of OpenStack's control plain. While instances remain running, neutron networking such as floating IPs may also be affected on the controllers.

How to completely delete /var/lib/mysql and bootstrap galera in Red Hat OpenStack Platform

How to shrink the ibdata1 file in Red Hat OpenStack after the deletion of a significant amount of data from the database