@r1 the way the rook-ceph works that you pass raw disk to the Debian host and then it creates the OSD and cluster, I have few issues with this:
Adding and removing k8s nodes is just few commands and very quick and zero downtime for apps, but if I am running rook-ceph, I need to rebuild the cluster every time I do that and thats extremely time consuming and extra over head.
The size of each VM that is being backed up daily/weekly is also extremely big and consumes a lot of resources and storage space.
Instead if you get a xcp-ng native local cluster that can be used by VM's as local block type SR that would simplify the implementation many times.